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LECTURE NOTES

GEO bates Y

Ourtine or tHe Geotogy or CANADA.

for the use of Students.

WITH

FIGURES OF CHARACTERISTIC FOSSILS.

J. W. DAWSON, LL.D., F.R.S.

MONTREAL: :
DAWSON BROTHERS, PUBLISHERS.
1880.

Entered according to Act of Parliament of Canoda, in the year 1880,
by Dawson Brorugrs, in the Office of the Minister of Agriculture.

-+ sw ee SESTIVWEON SNNUOS

CONTENTS.

Litno.oay.
Chemistry of Rocks .......ccecceceoes
Mineralogy of Rocks ........... oY.
Lithology proper ....... cesses
STRATIGRAPHY.

Origin of Rocks ....ccccceseccee

Hardening and Metamorphism...

Concretionary action............
Colours of Rocks .......cee0 cece
Markings on Rocks ......... 0605
Arranegement on the large scale .
Joints and Slaty Cleavage .......
Inclined Position of Rocks
DAU LGR ora vatove as kexernanie: sipiaaiece
Unconformability.........
Denudation ........ 2.066
Massive Rocks ...........
VOI Eilers presence ayes ge sasc
Chronology of Rocks.....

Maps and Sections...... ...66.

PALMONTOLOGY.
Preservation of Organic Remains.
Classification of Animals........

Classification of Plants..........

IV. HistoricaL Grouoay.
Eozoic Period........ cece eee ee aeiee ,
Paleozoic Period ........005 wees MORE ROT
IMGRBOZOIC POLIO} sisie.0 sie: cio 6 peaielaacbs sate b4 ieee las hace

KAIMOZOLC ROMO: s:sc:0re-s 5.3 be csabieee odd bd Fed a RSH

FIGURES OF FOSSILS. ...... sees eeee cence

eee

<1 arse SaSTTVNUON SINWUOS

° «

LECTURE NOTES

GEOLOGY.

FOR THE USE OF STUDENTS.

Geology, or, as it has been sometimes termed, Geognosy, is the
scientific knowledge of the earth; or more particularly of that
rocky crust of the earth on which its superficial features depend,
which affords to us mineral products and soils, on which animals
and plants exist, and in which are preserved the monumental
records of the changes which our planet has experienced in past
time.

Geology may be studied with reference to its practical pursuit
as a method of scientific investigation, or with reference to the
theories of the earth deducible from its facts, or with reference
to its applications to the arts of life. These several aspects of
the subject may be termed—

1. Practical Geology.
2. Theoretical Geology.
3. Applied Geology.

The first is that which should engage the attention of the
student at the outset, as being preliminary to the successful cul-
tivation of the others; but in studying it reference may be made
to its bearings on the second and third.

Practical geology may be arranged under the following general
heads :—

I. LirHoLoay—or the study of Rocks as mineral aggregates
and as materials composing the earth’s crust. This study is
best carricd on with the aid of properly named hand Specimens
of minerals and rocks, and is much aided by chemical tests and
by the examination of sections of rocks under the microscope.

II. SrratiagRaAPHy—or the consideration of the arrangement
of the rocky masses of the earth on the large seale. This
study requires the aid of maps and sections of the structure of |
portions of the earth, and is carried on in nature by the exami- 4
nation of natural sections and cliffs, quarries, mines, and other .
exposures of rocks,

III. PALmonroLoagy—or the study of the fossil remains of
animals and plants imbedded in the earth’s crust, in connection
with the succession of deposits ascertained by stratigraphical
investigation, This subject requires some preliminary knowledge
of zoological and botanical classification, and is studied by com-
parison of museum specimens and by collecting and determining
fossils, :

IV. HisroricAL Gro.oay is the application of all the above
to the geological history of the earth, and connects the elements
of practical geology with the theory and application of the
subject.
[In the regular University curriculum the student is supposed to
have given some attention to the elements of Chemistry, Botany and
Zoology. He is thus prepared in the ordinary course in Geology to
enter on the study of Lithology, Stratigraphy and Paleontology, and
in the honour course to go more fully into the determination of rocks
and fossils, and into local stratigraphy and descriptive and theoretical
geology.] 4

I, LITHOLOGY.
(1.) CHemistry or Rocks.

Of about sixty-three elements or simple substances known to
chemistry, only sixteen enter into the composition of the more
common rocks which constitute nearly the whole of the earth's
crust. These are, in the order of their relative importance :—

Non-Metallic Elements. Metallic Elements. :

Oxygen. Tron. y
Silicon. Aluminium. j
Sulphur. Calcium.
Chlorine. Magnesium.

Carbon. 3 Sodium.

Hydrogen. Potassium.

! Fluorine. Barium.
Phosphorus. Manganese.

“<8 0-331 TVWHON SAW a

Of the above only Oxygen, Sulphur, Carbon and Tron can
exist in nature in a pure or uncombined state, The more com-
mon minerals are all compounds of two or more elements,

Oxygen is the most important element in the crust of the
earth, since in the ordinary rocks the other elements almost
always occur in combination with this as oxides, Thus Silica
or flint is Oxide ot Silicon, Alumina the earth of clay is Oxide
of Aluminium, Lime is Oxide of Calcium, The ordinary ores
of Iron are oxides of the metal,

Next to Oxygen the most important element is Silicon:
Corfbining with Oxygen this forms Silica, and Silica has the
property of combining with many other elements to form Sili-
cates, which are the most common constituents of minerals and
rocks. Of these Silicates the most abundant are those of Alum-
inium, Calcium, Magnesium and Potassium; and these are
variously combined and mixed with one another to constitute
the more complex minerals and rocks. Silicates sometimes con-
tain water as an essential constituent, when they are termed
Hydrous Silicates, :

Other important Oxygen compounds are the Curbonates, Sul-
phates and Phosphates. Thus Calcium Carbonate is common
Limestone, Calcium Sulphate is Gypsum, and Calcium Phos-
phate is Apatite or Bone-earth.

Some important constituents of rocks are not Oxides, as Sodium
Chloride or common Salt, Calcium Fluoride or Fluorspar, Iron
Bi-Sulphide or Iron Pyrite.

There is a peculiar group of minerals and rooks of organic
origin into which Carbon ent..s as a principal ingredient.
These are the Coals, Asphalt and Bitumen.

(2.) MINERALOGY oF Rocks,

Of the chemical compounds above referred to, those which
constitute the majority of rocks are the following :—

1. Quartz or Silica,

. Felspar,

2
3. Miea. a
4. Hornblende. if Anhydrous Silicates.
5

. Pyroxene.

6. Tale \
7. Serpentine. Hydrous Silicates,
8. Chlorite. |
9

_ 9. Calcite.
10. Dolomite.

11. Gypsum. Carbonates, Sulphate,

; Phosphate, Fluoride,
Ee aye: and Ohloride.
13. Fluor Spar,

14. Rock Salt.
15. Magnetite.

16, Hematite. | Oxides and Sulphide
17. Limonite. j of Iron.
18. Pyrite.

19. Coal. \ ‘
20. Bitumen and Asphalt. Carbonaceous Minerals.
21. Graphite.

1, QUARTZ.

As familiar examples, Flint and Rock Crystal may be taken. The
former, occurring in concretions in chalk and other calcareous rocks,
was probably one of the first mineral substances used by man; being
the material of the flint implements of the “Stone age.” As quartz
is the most common of minerals, and occurs in most silicious rocks,
it may serve as a typical mineral whereby to illustrate the terms used
in other cases.

Composition.—Quartz when pure is Silica, a compound of the ele-
ments Silicon and Oxygen. The former is an element not unlike
carbon or charcoal in many of its properties; the latter a gas and
the mest important ingredient of the atmosphere. Silica is thus an
Oxide of Silicon, and containing two proportions of Oxygen to one of
Silicon, its chemical name is Silicon dioxide.

CRYSTALLIZATION.—Its usual form is a six-sided prism, terminated
by a six-sided pyramid. It thus belongs to the Hexagonal system of
crystallization. When mineral substances solidify from the state of
vapour, from solution in water, or from a state of fusion, their part-
icles tend to arrange themselves along certain. lines or axes, and thus
to produce crystals of definite geometrical forms. The law in the
case of Quartz is, that its particles arrange themselves along three
horizontal axes, or lines of attraction, at angles of sixty degrees with
each other, and along a fourth axis at right angles to the other three.
The six-sided plates and six-rayed stars of snow are formed on the
same principle.

eae ee SaSTTVAYON S4AWuOg

Perfect crystals of Quartz are found lining Geodes or cavities im
rocks, also the sides of fissures and veins, and sometimes imbedded
in the substance of rocks. Small crystals confusedly avgregated,
and imperfect, owing to pressure, give Granular varieties. Crystals so
small that they canrot be discerned by the naked eye give Crypto-
crystalline varieties.

Its Harpness is 7, measured by a scale in which Tale is 1 and
Diamond 10. The hardness of Quartz is sufficient to enable it to
scratch glass, to resist the action of steel, and to feel gritty in the
teeth.

Its Speciric Gravity is 2-5 to 2:8, measured by a scale in which
water is the unit. It is thus two and a half times heavicr than water.
Quartz being one of the most common minerals, and entering very
largely into the composition of rocks, in which also it is associated
with many other substances not very different in specific gravity, it
follows that its specific gravity is about that of most ordinary rocks ;
all of which are thus sufficiently heavy to sink readily in water, but
when immersed in water lose between one half and one third of their
weight.

OpticaL CHARACTERS.—Quartz is colourless, but becomes coloured by
mixture with other substances, especially Oxides of Iron. The
Protoxide (Ferrous Oxide) gives dull green and blackish colors—the
Peroxide (Ferric Oxide) red colours, and the Hydrous Peroxide yellow
and brown colours. The Lustre of Quartz is, with reference to its
kind, Vitreous or that of broken glass. With reference to its degree,
it varies from splendent, the lustre of perfect crystalline faces, to
dull or lustreless. The vitreous lustre is a good character whereby
to distinguish the mineral. The pure and crystalline varieties are
transparent ; the crypto-crystalline and coarse varieties translucent to
opaque. :

Quartz is Britile, and its fracture Conchoidal in the pure varieties.
It is Infusible and Insoluble in water and ordinary acids ; but may be
fused or dissolved in water, when combined with Alkalis, as Potash
or Soda.

VARIETIES OF QUARTZ,

Quartz presents many varieties, which may be arranged under the
heads of (a) Crystalline or vitreous, and (4) Crypto-crystalline.
(a). Vitreous Varieties.
Rock Crystai.—Transparent and colourless, often in the definite crys-
talline form. Used for lenses, for ornamental purposes and to

form imitation gems or doublets.

Amethyst.—Purple and violet varieties, coloured by a minute quantity
of Manganese, or perhaps in some cases by Iron and Soda.

Rose Quartz—A more delicately tinted gpk variety.

Yellow and Smoky Quartz.—Called C-‘yngorm or false Topaz, of smoky
or rich yellowish and brownish hues; coloured by Titanic Acid,
or by organic matter.

Cat's Eye.—Transparent Quartz, containing fibres of ashestus, which f
give it a lustre resembling that of satin.
Aventurine is translucent quartz spangled with bri!"-> scales of
yellow mica.
The glassy varieties of quartz pass into common milky quartz.

re ae ge

(b). Crypto-crystalline Varieties. \i
Chalcedony is the general name for colourless varieties having a
glistening and somewhat waxy lustre.

} Carnelian is a flesh-coloured or red chalcedony coloured by iron. A
deeper red variety is called Sard.

Agate is chalcedony with bands or spots of different textures and
colours. When these are in parallel layers it is called Onyz.
Some of the layers being absorbent, colourless agates of this kind
can be artificially coloured. When some of the layers are of car-
nelian or sard it is called Sardonyx. These banded varieties are
the material of Cameos. When translucent Chalcedony is pene-
trated with moss-like or dendritic filaments of Oxide of Iron or

i Manganese it is Moss agate or Mocha stone.

i Chrysoprase is a pale green variety coloured by Oxide of Nickel. Green
varieties coloured merely by Iron are common Prase.

Flint and Chert are names for coarse Chalcedonic varieties, usually
impure and of dull colours. A cellular variety is Buhr-stone,
used for millstones.

Agates are produced by the deposition of Chalcedony in the ca-

vities of rocks, usually those of volcanic or igneous origin. When
Hi this process is slow or intermittent, bands of various textures and
colours are formed in succession. Flint and Chert are formed by the
Li slow collection of silicious particles around centres, by concretionary

} action. Hence they often have fossil sponges, shells, &c., in their
interior. Wood imbedded in rocks is often fossilized by silica, or 4
silicified, so as to :esemble Agate. f

i
i
Jasper includes those varieties which are opaque and more or less
j deeply coloured, usually by Oxide of Iron. Red Jasper is one of
i the most common varieties ; a brown clouded or banded Jasper is
called Egyptian Jasper ; green and red or green and yellow banded
} varieties, are Riband Jasper ; & green variety with bright red spots
is Bloodstone or Heliotrope. q
Quartz occurs very largely in the earth’s crust as sand, sandstone
and quartz-rock or quartzite, and also as a constituent of many com-
pound rocks.

Ho awew a ESTTWWEON S4AWuos

2. FELSPAR.

There are several species of Felspar; but we may take as an
example the most abundant and most important species, Orthoclase or
common Felspar.

In Chemical Composition it is a Silic Se of Alumina and Potash. It
is not acted on by acids and is fusib)» with difficulty.

Its Crystalline form is monoclinic ; its particles being arranged in
accordance with three axes of cryst*ilization—the two horizontal
ones at right angles to each other, the third at an angle of 63°53’ to
plane of the others. It has a perfect cleavage parallel with the
base. These cleavage faces aid in distinguishing it from Quartz.

Its Hurdness is 6, being thus next to Quartz in the scale of hard-
ness. ‘I'hough scratched by Quartz it is hard enough to scratch glass,
but feebly.

Its Specific Gravity is 2-5 to 2:6.

Its Lustre is vitreous, but with a tendency to pearly on cleavage
surfaces. It is white when pure, but often has red tints due to the
presence of Ferric Oxide.

‘aolin, or the fines lina Clay, proceeds from the decomposition o

Kaolin, the finest China Clay, Is f the d t f
‘elspar; the Potash being dissolved by rain water and leavi
Felspar; the Potash being d lved by t 11 ng
the Silica and Alumina in a fine state of division.

Of the other Felspars the most important are Oligoclase and Albite,
Soda Felspars, in which Soda replaces the Potash of the Orthoclase,
and Labradorite and Anorthite, Lime Felspars, in which a large propor-
tion of Lime is present as well as Soda. Albite sometimes presents a
beautiful pearly opalescence upon its cleavage faces, and Labradorite
is remarkable for the splendid play of colours observed in some
specimens. Labradorite, Anorthite and Oligoclase are basic, or have
an excess of base relatively to their silica. All beside Orthoclase are
triclinic.

The Felspars are extremely important in Geology as constituents
of the Silicious Crystalline rocks, as Granite, Syenite, Gneiss, Doler-
ite, Porphyry, &e.

They enter very largely into the composition of the lavas of Vol-
canoes; those called 7rachytie Lavus or Trachytes, consisting princi-
pally of Felspar.

3. MICA.

Of this also there are several Species :“ Common Mica or Muscovite

is the most important.

It is a very complex Silicate, containing Silica, Alumina, Potash,
Tron, Magnesia, Lime and Soda.

Its crystals are inclined rhombic and rectangular prisms (mono-
clinic.) The angles of the rhombic prisms are 120° and 60°. It is
remarkable for its very perfect cleavage parallel to the base of the

prism. In this direction it may be split into extremely thin laminae
which are flexible and elastic. When crystallized in small radiating
plates it is called Plumose Mica.
H.—2-0 to 25. Gr.—2-75 to 3-1. }

Its lustre on the faces of the cleavage planes is metallic pearly,
and its colours range from silvery white to greenish, yellow and
black. They are due to Oxides of Iron.

Along with Quartz it forms Mica-scliist, and in a very fine state of
division it is largely concerned in giving cleavage to roofing slate.
It also gives a flaggy character to sandstone. In general when scales
of Mica are arranged in parallel layers in rocks they give to these
more or less of their own fissile character.

Biotite,a mica containing much magnesia and iron, and of a dark
colour, is next in importance to Muscovite.

4. PYROXENE.

}
The name of this mineral, implying that it is a “Stranger to fire,”
is a reminiscence of the old controversies as to the origin of rocks
i from water or heat, and is curiously contrary to the fact that Pyroxene
| is one of the largest constituents of volcanic rocks.
| Composition. Silica, lime, magnesia and iron. Some of the varie-
| ties have much more iron than others.
i Crystalline form monoclinic or like that of Orthoclase, but the
angles different, the inclination of the principal axis being 73° 59’,
and the acute angle of the rhombic prism, 87° 5’, so that it is nearly
; square. It occurs also in granular and fibrous forms. Its cleavage is
not perfect, but may be obtained parallel to the faces and bases of
} the prisms.

H.—5 to 6. Gr— 3:2 to 3-5.

It is thus almost as hard as Felspar, and somewhat heavier than
that mineral or quartz, so that rocks containing much Pyroxene are
usually somewhat heavy.

It is colourless, but assumes the colours due to Hires Oxide,
ranging from dull green to black. Its lustre is vitreous inclining to
resinous, and in some varieties it’ becomes pearly.

Varieties.
These are very numerous and have received different names. We

shall notice only a tew of some geological importance.

Augite or common Pyroxene. This is of dark colour, usually black ;
and is the form in which the mineral most commonly occurs as
an ingredient in rocks.

Sahlite and Malacolite are light green and white varieties, also occur-
ring sometimes as considerable ingredients of rocks.

Diallage is a variety with a very distinct cleavag:, and strong metal-
lic pearly lustre on the surfaces.

a ee Ne Ne A
ye

NUON A7NWNOS

5. HORNBLENDE.
This is a mineral closely allied to Pyroxene. Its ordinary varieties,
however, contain more magnesia and less lime than the latter.
Crystallisation monoclinic, but its rhombic prism is much flatter than
that of pyroxene, its obtuse angle being 124° 30’, and it has a
distinct cleavage parallel to the sides of the prism. It thus
forms flat blade-like crystals, and these being often long and
slender, it assumes fibrous forms.
H.—5 to 6. Gr.—2:9 to 3-4.
Its range of colour is similar to that of the last species.
Varieties,

Common Hornblende or Amphibole includes the dark and more massive

varieties.

Actinolite is green, and columnar or fibrous.
Tremolite is white or gray, and finely fibrous.

Asbestus includes the finest fibrous varieties, which from the slender-
ness and flexibility of the fibres, may be woven into fabrics
which have become celebrated as incombustible cloths.

Mountain Wood, Mountain Cork and Mountain Leather are fibrous and
lamellar varieties resembling the substances whose names they
bear,

6. TALC,

Is a silicate of Magnesia, with water. It is thus an example of a
Hydrous Silicate.

Crystallization trimetric, and usually occurring in foliated or cleay-
able masses, the cleavage being similiar to that of Mica. It also
occurs massive or crypto-crystalline.

,
H.—1. Gr.—2-5 to 2:8.

The low hardness of Talc affords a ready means of distinguishing
it from other foliated minerals. It has also a soapy or unctuous feel,
and its laminz are not elastic.

Its colour is usually light green, though sometimes a silvery white.
Its lustre is pearly.

Soapstone and Potstone, are compact or confusedly crystalline varieties,
used for firestones for furnaces, or vessels required to stand the
fire.

French Chalk is a variety used for marking.

Meerschaum is closely allied to Tale, but has a larger proportion of
water.

Tale is an ingredient in Tale Schists, to which it communicates its
own foliated character.

7. CHLORITE,

{

This represents a group of several species or sub-species. Chlorite

may be regarded as a Hydrous Silicate of Alumina, Magnesia, and

| Tron. It occurs in foliated masses and flat crystals, of a greenish
colour and slightly pearly lustre. It is harder than Talc, and its

' lamine are not elastic. It is the leading ingredient of Chlorite

Schists. 4:

} 8. SERPENTINE.

This is a Silicate of Magnesia with water, the latter in larger quan-

i} tity than in Talc. It usually occurs massive, and sometimes fibrous.

It sometimes constitutes considerable rock masses.

H.—2:5 to 4. Gr.—2:5 to 2:6.
Its colour is usually green, and its lustre somewhat resinous or
waxy.

Precious Serpentine, includes varieties of a rich green coiour and
translucent. Common Serpentine, includes the more dull-coloured
avd opaque varieties. Pierolite and Chrysolite are fibrous varieties.
Ophiolite or Verde Antique Marble, consists of a mixture of Serpen-
tine and Calcite, and is usually of green and white colours.

9. CALCITE.

Is Calcium carbonate, or common Limestone. Its effervescence
with acids, owing to the disengagement of gaseous Carbonic Acid,

is one of the ready ways of distinguishing it. Its inferior hardness,
enabling it to be easily scratched with a knife, aids in distinguishing
it from Quartz, Felspar and other hard silicious minerals.

Crystallization hexagonal. It occurs in many forms belonging to
this system ; especially the six-sided prism, the rhombohedron and
the scalenohedron. It has very distinct cleavage parallel to the faces
of the rhombohedron. It occurs also in granular, fibrous and crypto-
crystalline states, as well as in earthy conditions.

H.—3. Sp. Gr.—2:5 to 2:8.

It is colourless, but is often coloured oy other substances, especially
Oxides of Iron and Carbonaceous matter. Its lustre is vitreous, in-
clining to pearly on the cleavage faces. It varies from transparent
to opaque. The transparent varieties known as Iceland Spur possess
double refraction.

Varieties.

Calecareous Spar, includes the perfectly crystalline forms.
f Satin Spar, is a fibrous form occurring in veins, and having a silky
lustre.

Cale Sinter, is a general name, which may include the imperfectly

crystalline conditions occurring in Stadactites and Stalagmite, Con-
} gealed water, Gibraltar Spar, and Calcareous Tufa. All these
varieties are deposited from solution in water, aided by an excess
of carbonic acid.

VAUON SInWuOd

10. DOLOMITE.

This is Calcium and Magnesium carbonate. It effervesces less
readily with acids than Calcite. Its crystallization is rhombohedric
like that of Calcite, except that the angles of its rhombohedron are
slightly different, and it is a little harder and heavier. It has also a
more pearly lustre.

Dolomite occurs in nature in the same manner as Calcite, but often
contains ferrous carbonate, which causes it to assume a rusty colour
in weathering.

11. GYPSUM.

Sulphate of Calcium with a large proportion of water (about 20
per cent). Its crystallization is monoclinic, and it has a very distinct
cleavage, parallel to the larger faces of the rectangular prism. It is
found in foliated, fibrous and granular crystallizations, and sometimes
occurs in thick beds. Finely granular and translucent varieties are
used for ornamental purposes, under the name of soft or gypseous
alabaster. Its softness, enabling it to be scratched with the finger
nail, and its pearly lustre, are distinguishing characters.

H.—1:5 to 2. Gr.—2-31 to 2-33.

Its lustre is pearly upon the cleavage faces. It is colourless, but
frequently stained red by Peroxide of Iron, and sometimes black by
carbonaceous matter.

Selenite is a lamellar variety of gypsum. Fibrous varieties are used
to imitate Cat’s eye.

The readiness with which Gypsum parts with its water when heated,
and resumes it, becoming solid or setting, when mixed with water,
gives the substance important economical uses for casting, plastering
and cements. It is the cheapest means of supplying Sulphuric Acid
to the soil, and to manures, and thus is of some value in agriculture.

Anhydrite is gypsum without water. It is found with the previous
species, from which it differs in its greater hardness and specific
gravity, and its trimetric crystallization. It is sometimes used as
an ornamental stone in the same manner as marble.

12, APATITE.

This is Calcium Phosphate, and is of great interest as represent-

ing the earthy part of the bones of animals.

Its crystallization is hexagonal, and its usual form, is the hexa-
gonal prism.

H—5. Gr—3- to 3-2.

Its lustre is resinous, and its colour usually greenish,

In the crystalline state it occurs largely in veins and beds in the
Laurentian formation in Canada. It is also found in concretionary
masses, in beds of various geological ages, and is the principal ccn-
stituent of the harder varieties of Guano.

Calcium Phosphate is an essential ingredient in soils, in which
it is usually present in very small quantity, and it is rapidly removed
by those crops which produce the greatest amount of animal food.
‘This gives to it a very great importance in agriculture, and it is much

sought for in every civilized country, and largely used as a means of
improving the soil.

13, FLUOR SPAR OR FLUORITE.

This is Calcium Fluoride. Its crystalline form is monometric,

and it often occurs in beautiful and regular cubes, with a cleavage
parallel to the faces of the octahedron.

H.—4. Gr.—3-1 to 3-2.

It is colourless, but is of blue and purple colours, and sometimes
red or yellow.

It frequently occurs in metallic veins, more especially with the
ores of load. It has been used as a flux in reducing metallic ores,
hence its name Fluor.

14. ROCK SALT.
Common Salt is Sodium Chloride.

It crystallizes in the mono-
metric system, usually in cubes.

H.—2. Gr.—2: to 2:7.

It furnishes an excellent example of a soluble native Salt. It

occurs not only in great quantity in the sea and in salt lakes, but also
in extensive beds in the crust of the earth, whence it is mined for
use. These beds have probably been formed by the drying up of salt
lakes, and of isolated portions of sea water, and the subsequent
covering by sediment of the beds of salt thus formed. Copious salt
springs often rise from such deposits.

15. MAGNETITE. ,

Is an Oxide of Iron intermediate between the Monoxide and Sesqui-
oxide. Crystallization monometric, usually in octahedrons.

H.—5-5 to 6:5. Gr.—5.

Colour black, Lustre metallic. It occurs in Canada in large beds,

in the Laurentian, and also in layers as Iron Sand, and is the most

valuable of the ores of Iron. It is attracted by the magnet, and it

sometimes has itself magnetic polarity, constituting the natural load-
stone. It is distinguished from the other species by its black powder
or streak and its magnetic properties.

16. HEMATITE,

Also called Specular Iron, is Sesquioxide of the metal. Its crys-
tallization is Hexagonal, and it often occurs in thin plates or scales,

and also in fibrous forms.

5:3.

H.—5:5 to 6-5. Gr.—4-5 to

"SSSTTVWYON ATNWUOS

Its colour is black or steel grey, but its streak or powder is deep
red. It is not usually attracted by the Magnet.

Foliated varieties constitute Micaceous Tron Ore, compact or fibrous
‘dull red varieties are called /ematite, and carthy varieties are Red
Ochre. It is a very valuable ore of Iron.

17. LIMONITE.

This is Hydrous Sesquioxide of Iron. It occurs in fibrous and
concretionary masses.
H.—5: to 5:5. Gr.—3-6 to 4.

Its colour is dark brown, and its streak or powder yellow. Com-
pact and fibrous varieties are called Brown Hematite. Concretionary
varieties found in modern deposi's are Bog Iron Ore, and earthy
It is a valuable ore of Iron.

varieties are Yellow Ochre.

18. PYRITE.

Is Disulphide of Iron. Crystallization monometric, usually in
cubes and octahedrons.
H.—6: to 65. Gr.—4-8 to 5.

Colour, bronze yellow. It is avery common mineral, and is often
mistaken for gold and for valuable metallic ores. When mixed with
metallic ores and with coal it is a troublesome impurity ; but it is
used as source of Sulphur and Sulphuric Acid, and of the Ferrous

Sulphate.

19. COAL.

Coal essentially consists of compounds of Carbon and Hydrogen,
with variable amounts of Oxygen, of Nitrogen and of earthy matter.
It presents many varieties, which shade into each other and differ
much in composition and physical properties. This results from the
fact that it is not a definite chemical compound, or crystallized mineral
species, but rather a product of the partial decomposition of vegetable
matter buried in the earth.

Its vegetable origin is proved by the remains of plants imbedded in
it, and often showing their structure distinctly under the microscope,
and by its resting on under-clays containing roots of trees, overlaid
with shales filled with impressions of plants. It is of different geolo-
gical ages, but the greater part was formed at a particular part of the
earth’s geological history, known as the Carboniferous period.

Its hardness varies from 1- to 2-5, and its sp. gray. from 1: to 1-8.
Its colour is black, or dark brown, its powder either black or brown.
Its lustre is resinous or sub-metallic, and its fracture conchoidal or
flat. It usully presents a laminated structure, with layers of mineral
charcoal, or of vegetable debris, or of earthy matter, between the
lamin, which often consist principally of flattened trunks of which
the coal has been made up.

The principal varieties are the following :—

Brown Coal, is an imperfect coal found in the more modern formations,
It is often merely a consolidated peat, but when composed of flat-
tened trunks of trees, it assumes the compact form of jet It is in-
termediate in composition between Coal and Wood. It contains
from 47 to 70 per cent of carbon, and from 5 to 18 per cent of
Hydrogen, the remainder being Oxygen and ashes. It is usually
an inferior kind of fuel.

Bituminous Coal, or ordinary black coal, proceeds from a more perfect
carbonization of vegetable matter, and is the coal of the true Car-
boniferous system. The coking varieties become soft when heat-
ed, and burn with much flame, The non-coking varieties do not
soften, and contain less gaseous matter. Bituminous coal contains
from 75 to 90 per cent of Carbon, and from 8 to 6 per cent of Hy-
drogen, the remainder being princivally Oxygen and ashes. ‘The
Bituminous varieties are used for the production of gas.

Anthracite, proceeds from the alteration of Bituminous coals, and is
sometimes of the nature of natural coke. It is harder and heavier
than the Bituminous coals, and contains from 85 to 92 per cent of
Carbon, and from 2 to 3 per cent of Hydrogen. It gives little or no
flame in burning. In some coal deposits, Anthracite passes by a
further process of alteration into Graphite or Plumbago, which is
however regarded as a distinct mineral species, owing to its very
different physical properties.

20. BITUMEN.

Mineral oil and mineral pitch are mixtures of different hydro-carbons
differing from coal in their liquid, viscid or easily fusible character,
and in being soluble in oil of turpentine and ether. Like coal, these
substances are derived from the chemical change of vegetable matter
buried in the crust of the earth ; but they result chiefly from marine
vegetation, or from that which has been buried and excluded from
the air while still recent.

Petroleum, or mineral oil, includes the liquid or viscid varieties which
flow from natural oil wells, or are obtained by boring into the
beds of rock containing this substance in their pores or fissures,
It has been known and used from the most ancient times, but
has recently acquired greater importance from the abundance of
it obtained by boring, and the means discovered for its purifi-
‘ation. Petroleum often contains more than 12 per cent of
Hydrogen.

Asphaltum, includes the solid and semi-solid varieties, having a
specific gravity similar to that of coal, and pitchy lustre with a
black or brownish black colour. It contains from 7 to 9 per
cent of Hydrogen, and sometimes a considerable proportion of
Oxygen and some earthy impurities. It is found in veins and
beds, and has proceeded from the alteration and hardening of
petroleum, owing to the loss of its more volatile ingredients.

VWUON aINWHOS |

Albertite, and “ Levis Coal,” ave asphaltic minerals still further al-
tered, until they assume nearly the appearance and composition
of the bituminous coals, They are found'in veins or fissures,
and not in beds like the true coals, and have no vegetable
structure. In some altered rocks materials of this kind have
been converted into Anthracite and probably into Graphite,

Earthy Bitumen, and Cannel Coal are materials of this series, mixed
with much earthy matter, and hardened until they resemble true
coa's. They are found in beds associated with the ordinary coals,
and are much used in gas-making and for the distillation of
Coal Oil.

It will be seen that the Coals and Bitumens form two parallel series,
according to the amount of chemical change which they have ex-
perienced, thus :—

COAL SERIES, BITUMEN SERIES.

Vegetable Matter. Vegetable Matter.
Peat. Petroleum.
Brown Coal. Asphaltum.
Bituminous Coal. Cannel Coal.
Anthracite Coal. Anthracite.
Graphite. traphite.

21, GRAPHITE.

This substance is Carbon with its molecules arranged in a peculiar
manner, constituting an allotropic form. Its crystalline form is
hexagonal, in flat six-sides tables.

H.—1.to 2. Gr—2.

Colour black and steel grey ; Streak black. Lustre metallic.
Divides into thin lamina, flexible and greasy to touch.

Graphite is probably in most cases a coa! or asphalt, altered by heat,
and in this way it is often formed accidentally in furnaces. It is
largely used in making crucibles for melting metals, in coating iron
castings, in lessening the friction of machinery, and in drawing and
writing. Its common names of “ Black Lead” and Plumbago are in-
appropriate, as it contains no lead. The name Graphite is derived
from its use in writing.

[For the numerous other species of minerals occurring dissemi-
nated in rocks or in veins and otber repcsitories, the student is re-
ferred to text books of Mineralogy.]

(3.) LitnoLoay Proper.

Some rocks, a8 quartz rock and limestone, are definite chemi-
cal compounds, and consist of one mineral species only ; but
even these are often mixed with foreign matters; and the greater
part of rocks are mixtures of different mineral substances in
various proportions, As these mixtures are regulated by no
definite law of proportion, it follows that such rocks pass into
each other by indefinite gradations. Hence the nomenclature
and classification of rocks are attended with many difficulties,

For purposes of practical geology it is important to consider
the classification of rocks under three aspects.

1, With reference to their Origin, rocks may be :—

(a) Aqueous or Sedimentary, that is, they may have been
deposited as sediments, as sand, clay, &c. in water, and such
deposition may have been aided or modified by accumulations of
organic matter, as shells, corals, drifted plants, &e.

(b) Igneous or Aqueo-igneous—products of the action of heat
in the interior of the earth. Of this kind are lavas, scoria,
pumice, and volcanic ashes,

(c) Metamorphic—that is they may be sediments or volcanic
beds which have been so modified by heat or pressure as tO as-
sume a crystalline condition accompanied in many cases by some
chemical change.

2. With reference to their Predominant Chemical Ingredients,
rocks may be regarded as (a) Silicious, (b) Argillaceous, (¢)
Calcar.ous, (d) Carbonaceous, (e) Ferruginous, The Silicious
rocks, which are by far the most abundant, may further be di-
vided into those that are Acidic or have an excess of Silica, and
those that are Basic or have an excess of the elements with
which the Silica is combined.

3. With reference to their Texture, rocks may be :—

(a) Fragmental, or composed of broken-up remains of older
rocks, Of this kind are conglomerates, sandstone and clay.

(b) Crystalline, or composed of crystals of one or more mine-
rals united together. Of this kind are granite and crystalline
marble.

(ce) Organic, or retaining the structure of organic bodies, as
coral and crinoidal limestones, and coals,

“SINWHOS

The above grounds of classification are of course allied with
each other, Thus fragmental rocks are for the most part aqueous,
The crystalline rocks are for the most part of igncous or meta-
morphic origin, though some, like gypsum and rock salt, are
aqueous, We may thus adopt one of the above arrangements as
the dominant or general one, and use the others in subordination
to it; und the first consideration or that of origin is probably at
present the most available for the larger groups. Our general
division of rocks may therefore be as follows :—

Class I. } including { (1) Volcanic or Superficial.
Iangous Rocks. (2) Hypogene or Nether.

Class IT. ‘ « § (1) Unaltered.,
including :
Aqueous Rocks. (2) Altered or Metamorphic.
Ciass L—IGNFOUS ROCKS.
Section 1, VouLcanic.

These are superficial products of Igneous action. All of them are
Silicates, having usually Aluminium, Calcium and Magnesium as the

principal bases. They may be divided into sub-sections, in accord-
ance with the proportions of acid and base, as follows :—

Sub-section 1. Basie Volcanic Rocks.

Doleritic Lava is poured forth in a molten state by modern volcanoes
and consists of Pyroxene with basic Felspars. It generally presents
a vesicular appearance, caused by the expansion of included vapours
and gases, and it has usually a dark colour caused by the presence
of iron in low states of oxidation. In ancient lavas the vesicles
often become filled by aqueous infiltration with various minerals,
when the texture of the rock is said to be Amygdaloidal.

Basalt is a dark-coloured finely crystalline compact lava which
often exhibits columnar structure.

Sub-section 2. Acidic Voleanie Rocks.
Trachytie Lava is a light-coloured lava containing an excess of
Silica, and produced by volcanoes in the same manner with ordinary
lava, It is vesicular, and when highly so passes into Pumice.

Trachyte is a more compact rock of the same character, consisting
chiefly of orthoclase, usually with a little hornblende and mica.
When quartz is present it becomes Quartz-trachyte. It is more or less
finely crystalline, and sometimes has imbedded crystals of orthoclase
felspar, giving it the texture known as porphyritic.

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Obsidian and Pitchstone are volcanic glasses of similar composition
to trachyte but vitreous in texture.

To this section belong volcanic Agglomerate and volcanic Tuff.
These are fragmental deposits made up of the stones and dust ejected
from volcanic orifices. Their materials may either be those of the
basic or acidic lavas or a mixture of both. They are strictly volcanic
rocks, though their materials are often arranged in beds and subse-
quently consolidated by the action of water.

Section 2. P.LuTonic.

These are the nether or underlying products of igneous action.
Being slowly cooled they are more highly crystalline than the rocks
of the previous section, and having been consolidated at great depths
below the surfaee, they do not become visible till after the removal
of the more superficial volcanic products. Hence the rocks of this
section visible at the surface are usually of greater age than the vol-
canic rocks.

Sub-section 1. Basic Plutonic Rocks.

Dolerite consists of the same material with Doleritic lava, and passes
into it; but its more crystalline varieties may be regarded as Plutonic.
When it contains hydrous minerals, as chlorite, it constitutes the
variety Diabase.

Diorite or Greenstone is a crystalline mixture of {ornblende, usually
dark coloured or greenish, with a triclinic felspar. 'This and the pre-
vious rock present great varieties of coarse and fine crystallization.

Syenite is a crystalline mixture of Hornblende and Orthoclase or
Potash Felspar. By the addition of quartz it becomes an acidic rock
and passes into Hornblendic Granite.

Sub-section 2. Acidic Plutonic Rocks.

Granite is a crystalline mixture of Felspar (Orthoclase with Oligo-
clase, or Albite) with Quartz and Mica. It may be coarse or fine
zrained, and sometime~ becomes porphyritic by the admixture of large
felspar crystals. Hornblendic or Syenitic Granite contains hornblende
with or instead of mica. Protogine contains talc as well as mica.
Graphic Granite is a variety found in veins. It is destitute of mica,
and has the quartz arranged in plates in accordance with the cleavage
of the felspar.

Felsite is a hard, finely crystalline or compact mixture of Felspar and
Quartz. It is sometimes called Petrosilexz and Felstone. When distinct
crystals of orthoclase felspar are developed in it the porphyritic tex-
ture is produced. This is ordinary or Felsite porphyry, but other
igneous rocks may assume the porphyritic structure.

The above are only a few of the more ordinary igneous rocks which
should be known to the student by specimens and if possible also by
their microscopic structure.

Crass II—-AQUEOUS ROCKS.

Section 1. UNALTERED Aqueous Rocks.

These may be produced either by the mechanical distribution of
sediment in water, by chemical precipitation, or by the accumulation
of the remains of animals and plants. The principal kinds are the
following :—

Conglomerate consists of pebbles of hard, usually silicious, rocks,
united by a paste or cement which may be silicious, argillaceous, cal-
careous or ferruginous. Conglomerates are beds of gravel, and they
indicate the somewhat powerful action of water as an abrading and
removing agent. They have often been formed along old lines of
coast, and are consequently irregular in their bedding and limited in
their horizontal distribution. The terms Volcanic Breccia and Agglo-
merate are applied to rocks composed of angular fragments. Volcanic
agglomerate has ‘already been referred to; but besides this Breccias
are accumulated by aqueous agencies in caves and fissures, and are
also derived from the debris of hard rocks disintegrated by frost, and
spread out by water without rounding of the edges.

Grit is a rock composed of coarse sand or small stones, and is in-
termediate between the last rock and the next.

Sandstone is composed of grains of sand, more or less firm, and either
angular or rounded, cemented together. When mixed with clay it
becomes argillaceous sandstone. When cemented by carbonate of
lime it is calcareous sandstone. Its grains are often superficially
stained of red or brown colours by the oxide of iron. Freestone is a
term applied to the softer and more easily worked sandstones ;

Flagstone to the laminated varieties. The harder varieties pass into ,

Quartzite. Greensand is a variety coloured by grains of the hydrous
silicate named giauconite. Sandstones with the surfaces of bedding
and lamination covered with plates of mica are micaceous sandstones

Shale is hardened clay or mud having a laminated texture, due
either to original deposition in layers or to subsequent pressure. On
the one hand it passes into soft clay, on the other by metamorphism
into slate. Arenaceous shale is mixed with fine sand and passes into
sandstone. Carbonaceous shale is mixed and blackened with coaly
matter. Bituminous shale or Pyroschist is impregnated with bituminous
matter. Calcareous shale contains limestone in a fine state of division
and effervesces with an acid. Fireclay is a soft variety rendered in-
fusible by the absence of alkaline matter. It is often associated with
beds of coal. Kaolin is a fine clay resulting from the decomposition
of felspar. Loess is the alluvial mud deposited in lakes and rivers.
Loam is a mixture of sand and clay.

Limestone includes all the unaltered rocks composed of calcium
carbonate, or calcite. It is distinguished by its softness as compared
with quartz and most of the silicious stones, and by effervescing with

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SSS

nERSREEERRERmenEENEENENN IETS Seer

22
an acid. It may be earthy, compact, crystalline, massive or laminated
in structure; or with reference to matters mixed with it, argillaceous,
bituminous; ferruginous, or cherty. Oolite is a variety composed of
minute rounded concretions, which often show under the microscope
a radiating prismatic structure as well as concentric lamination.
Travertin or Calcareous Tufa is a limestone deposited by calcareous
springs. Stalactite and Stalagmite are similar matter deposited on the
roofs and floors of caverns. By mixture with fragments of limestone
or of bone, Stalagmite may become a calcareous or bone Breccia.

Coral and Shell Limestone and Crinoidal Limestone, or more generally
Organic Limestones, are composed of fragments of calcareous organisms,
sometimes apparent to the eye, in other cases visible only under the
microscope. Chalk is an organic limestone made up of tests of Fora-
minifera mixed with the minute organic bodies named Coccoliths.

Dolomite is a double calcium and magnesium carbonate. It may be
distinguished from common limestones by its higher lustre, slightly
greater weight, failure to effervesce with cold acid, and by often
weathering of a rusty colour in consequence of the presence in it of
ferrous carbonate.

Marl is an earthy mixture of calcium carbonate with clay or sand.
The calcareous matter is sometimes in a fine state of division and
sometimes as fragments of shells (shell-marl). Marl is distinguished
from ordinary clay by eifervescing briskly when treated with an acid.

Gypsum, sc Calcium Sulphate, is of less common occurrence than
limestone, but sometimes constitutes thick beds of great purity.
Anhydritz is often associated with the ordinary hydrous variety.

Coal and carbonaceous rocks have already been referred to under
the heading of Minerals.

Tron ores have also been noticed under the same heading.

Section 2. Mrvramorpuic Rocks.

These are rocks originally aqueous or aqueo-igneous, which have
been subjected tothe action of heat and pressure, along with chemical
agencies, until their particles have so rearranged themselves as to
give a crystalline character accompanied by differences in the state
of combination of the contained elements.

The metamorphic rocks are intermediate in character between the
unaltered aqueous and the plutonic series. On the one hand they
pass into ordinary aqueous rocks, on the other by becoming highly
crystalline and losing their original bedding, they graduate into plu-
tonic rocks. The principal varieties of these metamorphosed rocks
are the following :—

Quarizite or Quartz Rock is a result of the alteration of sandstone
whereby its grains of sand become inseparable and sometimes indis-
tinguishable.

Gneiss is a product of the alteration of sediments, containing sufti-
cient basic matter for the production of felspar and hornblende or
mica. It thus resembles granite in composition, and is distinguished
by its laminated structure and stratified arrangement. Many gneisses
may have originally been bedded trachytes or volcanic tufts.

Mica Schist is a crystalline mixture of quartz and mica. It is a pro-
duct of the alteration of shales. It often contains disseminated
minerals, as pyrite, garnet or chiastolite. By addition of felspar it
passes into gneiss. By increase of quartz it becomes micaceous
quartzite or quartz schist, and by diminution of its crystalline charac-
ter it passes into Argillite.

Argillite or Clay Slate is a product of the alteration and hardening
of clay or shale. 1t is remarkable for the development in it of slaty
structure, Which arises from the forcing by lateral pressure of all flat
particles in a soft mass into positions in which they lie at right angles
to the direction of pressure. In this way the most perfect lamination
is often produced in planes quite different from those of bedding.

Hornblende Schist is a laminated mixture of hornblende with quartz,
and sometimes with mica. :

Tale Schist is a slaty rock in which talc takes the place of mica.
Chlorite Schist is a similar slaty rock consisting largely of that
mineral.

Nacreous or Hydro—mica Schist is « name which has been given to
crystalline slates in which a hydrous mica takes the place of the
ordinary mica.

Marble or Crystalline Limestone and Crystalline Dolomite include the
varieties of these rocks in which a perfect crystallization and often a
white colour have been developed by metamorphism. Ophiolite is a
marble containing grains or streaks and patches of serpentine.

Anthracite and Graphite result from the alteration of coal or of
bituminous matter. Thus ordinary coal passes, under alteration, into
anthracite, and finally, in certain cases, into graphite, and bituminous
shales pass into graphitic slates.

Magnetite is very often a product of the metamorphism of ores con-
sisting of the sesquioxide of iron. ‘

Local metamorphism can often be observed at the contact of
aqueous rocks with the larger igneous masses, and a study of
these cases affords a key to the explanation of those larger ex-
amples in which no obvious cause of alteration is present.
Metamorphism is induced or favoured by heat, by pressure, and
by the percolation of heated and mineral waters; and rocks of
complex character and containing basic and acidic minera) “ .ter-
mixed are those which present the most remarkable met 11, «i¢

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II. STRATIGRAPHY.

1. CAUSES CONCERNED IN THE PropvucTION oF Rooks,

This and the four following sections may be regarded as inter-
mediate in their character between Lithology and Stratigraphy,
or as introductory to the latter.

In nature there is a constant struggle between aqueous and
igneous agencies in modifying the materials of the earth’s crust.
The deeper portions of the crust are being slowly softened and
crystallized under the influence of heat and pressure, and are
thus being converted into metamorphic rocks, and these finally
into plutonic masses, portions of which being erupted constitute
voleanic products, On the other hand the waters and the atmos-
phere are constantly decomposing and wearing away the crystal-
line rocks at the surface, and depositing their detritus in the
bottom of the waters. These processes seem to have been active
throughout the whole of geological time in producing igneous
and aqueous rocks. Since however the latter are the more im-

, portant in geology, on account of their greater relative abund-
ance, their regularly bedded character and the fossils they con-
tain, we may direct our attention principally to them.

Atmospheric Erosion.—We have seen that the most common
crystalline rocks are composed largely of silicates, as the Felspars,
Hornblende and Pyroxene. When these are exposed to the
action of the atmosphere and of rair water, which always holds
| carbon dioxide in solution, the soda, potash, lime, and other
bases which they contain in combination with silica, are gradu-
. ally removed in the state of carbonates, leaving the alumina and
' silica behind in an incoherent state. Thus from the decay of a
hornblendic granite there may result quartz-sand, clay, lime-
stone, and iron oxides, which when sorted and variously de.
posited by water, may assume the a} 9carance of distinct alter-
nating beds, while the alkaline matters removed in solution are
washed into the sea or into lakes, where they may aid in chemical
changes leading to other kinds of deposition.

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To the atmospheric agencies we may also add the disintegrat-
ing power of frost, which by the expansion in the act of freezing
of the water contained in rocks, chips off sand and fragments,
and rapidly reduces very hard rocks to ruins. In mountains
and the polar regions this action of frost is aided by the mechan-
ical movement of glaciers, which removes to lower levels or into
the sea the material disintegrated by frost, and which also exer-
cises a polishing and abrading effect on the subjacent surface.
The action of coast ice, which is also very powerful, may rather
be classed with aqueous agencies.

Aqueous Erosion.—-This takes place by the abrading action of
rivers and torrents, by the beating of the waves on coasts, by
tidal currents, by the action of cold heavy currents on the sea
bottom, and by the solvent action of springs and other subterra-
nean waters. As these agents are constantly at work, the changes
which they produce in the lapse of ages are very great. It has
been estimated that the atmospheric and aqueous causes of
erosion at present in action, would suffice to remove the whole
of the dry land into the sea in about six millions of years.

Deposition.—The materials thus set free by chemical ¢ecom-
position and mechanical abrasion are deposited in layers ia the
depressed portions of the earth’s crust occupied by the waters.
The coarser materials, as pebbles and sand, may be thrown down
along coasts and at the mouths of rivers ; the finer materials will
be carried farther out to sea, and those held in solution may be
ultimately fixed in the organisms of coral animals and other
marine creatures, and may form coral limestones and similar
organic deposits.

In any given locality all these agencies, whether of erosion or
of deposition, may be greatly modified from time to time by

. changes of level or of climate, whether arising from movements

of the earth’s crust, or from astronomical causes ; and also by
voleanic paroxysms breaking forth from time to time.

2. HARDENING AND ALTERATION OF AQUEOUS Deposits.

Aqueous deposits thrown down by crystallisation may be hard
from the first ; but sedimentary beds are usauily at first soft, and
are hardened by subsequent processes, such as the following :—

(a) By Pressure of a great thickness of superincumbent ma-
terial. In this way, for example, soft clay is hardened into

shale, and peat into brown coal; and there is reason to believe
that lateral pressure, occasioned by folding and settlement of the
earth’s crust, may produce still more powerful effects in harden-
ing and crystallizing rocks. Pressure may act by condenging
soft sediments to a fraction of their original thickness, by arrang-
ing flat particles in the same plane, thus causing lamination or
cleavage, by causing minute particles to adhere by contact and
by developing heat.

(b) By Infiltration of mineral matter in solution. Subter-
terranean waters usually contain calcium bicarbonate, soluble
silicates or other mineral substances in solution, and depositing
these in the interstices of sand, gravel, fragments of shells, &c.,
may ultimately cement such materials into a compact rock.

Fig. 1.—Fragment of Trenton Limestone, magnified. It is composed
of broken pieces of corals, crinoids and shells cemented
together by transparent calcite.

(c) By Heat. When sediments are buried to so great a depth
that they are acted on by the earth’s internal heat, or when heat
is developed by the movement and crumpling of great masses of
rock, or when sediments are invaded by intrusive molten rocks,
they become baked and hardened, and in some cases their par-
ticles are enabled to arrange themselves as distinct crystalline

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minerals or to enter into new chemical combinations, The re-
sult is metamorphism, which as already stated may change mud
or voleanic ashes or similar incoherent material into the hardest
and most crystalline rock. It is farther to be observed that the
heat to which sediments are subjected at great depths, is not dry
heat, since their substance is saturated with water, and this
being prevented by pressure from escaping, remains in a heated
state, and must greatly promote chemical and molecular changes.

3. ConoreTIONARY ACTION,

An important modification of these hardening processes results
from concretionary action, ‘This is an unequal hardening of the
mass, whereby certain portions of it become indurated into balls,
nodules or grains. It depends on molecular attractive movements
collecting together certain constituents of the mass, and may pro-
duce the following kinds of concretionary structure :—

(a) The whole mass of material may assume a concretionary
structure, aggregating itself into nodular grains. This is the case
with Oolitic limestones and Oolitic ores of iron. A similar change
sometimes occurs f the cooling of igneous masses. (Fig. 2.)

Fig. 2.—Magnified section of Jolitic Limestone (after Sorby), showing
concretions with radiating and concentric structure, and
some of them enclosing fragments of shells, &c.

(b) Foreign materials diffused through the mass may be col-
lected into limited spaces, and thus form concretions, This is
the case with flints in chalk and with clay ironstone in beds of
shale.

(c) The cementing substance of the mass may be unequally
collected in certain portions at the expense of the rest. This
occurs in the hard concretions in clays and in “bull’s-eyes”’ in
sandstones,

Fig. 3.—Rounded concretion containing a fossil fish, split open.
Post-pliocene, Canada.

Any foreign body, as a fossil or a grain of sand, may form a
nucleus for a concretion. (Fig. 3.) Concretions have often a
concentric lamination marking their stages of increase. They
are sometimes hardened at the surface while the interior remains
soft, and the latter may subsequently crack from shrinkage.
When these cracks are afterwards filled with other mineral
matter, septaria concretions result. Concretions often assume
very fantastic shapes, and have been mistaken for fossils.

Geodes, which are cavities in rocks lined with crystals, are
distinct in their mode of formation from concretions, though
sometimes confounded with them.

4, CoLours oF Aqurous Rocks.

The most abundant colouring matter in rocks is iron. Its
monoxide and sulphide when diffused through sediments produce
green, gray and blaekish colours. Its sercioxide produces red
colours. Its hydrous sesquioxide gives ) | .w, buff and brown
shades. Peroxide of manganese is sometimes a cause of black
colours in rocks, and coaly matter is also a not infrequent cause
of the blackening of sediments.

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The following facts are important with reference to the colours
produced by iron :—

(a) In the subaerial decomposition of most rocks a sufficient
quantity of sesquioxide of iron is produced to colour the result-
ing sands or clays. In ordinary circumstances it is the brown
or hydrous oxide that is produced in this way; but in warm
climates, under the influence of volcanic heat and in the presence
of saline waters, the red oxide is produced. Thus the subaerial
decomposition of crystalline rocks coloured gray, green or black
by sulphide or monoxide of iron, gives rise to brown and red
sediments.

(6) If the sediments thus coloured are rapidly washed down
and deposited in the sea, or in limited areas of fresh or salt
water, they may retain their colours, and thus the red, brown
and purple sandstones and clays so characteristic of certain for-
mations are produced.

(c) If the sediment is long abraded by moving water, the
clay is separated from the sand, and the superficial red coating is
washed from the latter so that it loses its colour. In this way
gray or white sandstones are often found to alternate with red
or reddish shales,

(@) When sediments coloured with iron are deposited in fresh,
water along with organic matter, as peat, &c., the latter deprives
the iron of a portion of its oxygen, reducing it to monoxide, and
this being soluble in the acids naturally produced by the decay
of the vegetable matter, is removed, leaving the sand or clay in
a bleached condition.

(e) When the deoxidising process occurs in sea water, the
sulphates present in the latter being decomposed at the same time
with the iron oxides, a black iron sulphide is produced, which
gives a gray colour more or less dark to the sediment. Material
coloured in this way becomes buff or brown on weathering, and
becomes red when heated in the air. This is a useful mark of
marine clays. In this case or the last, scattered organic frag-
ments deposited in red sediments and not in sufficient quantity
to affect the colour of the whole, produce gray or white stains.

(f) If organic matter be present in large quantity, it not only
removes the red colour but communicates its own black or dark
brown colours to the whole.

_.The above considerations serve to show why red rocks have

been deposited in large quantity in times of physical disturbance
and voleanic activity, and generally when deposition is rapid and
organic matter absent, They also serve to explain the presence
of red beds with rock salt deposited from the waters of saline
lakes or lagoons, They also explain the rarity of fossils in red
rocks, since the retaining of the red colour implies scarcity of
organic remains, and an excess of peroxide of iron tends to
oxidise and destroy such as may be present. On the other hand
they show why gray and dark coloured beds are those which
most abound in fossils,

5. MARKINGS ON THE SurFACES OF AQusEous Rooks.

The circumstances under which aqueous beds have been de-
posited are often indicated by the markings seen on their surfaces,

(a) Ripple marks, caused by the motion of currents throwing
up slight ridges and hollows at right angles to the direction of
the current.

(b) Current lines, caused by the driftage of sand, organic frag-
ments, or sea-weeds and drift wood, in the direction of the current.

(c) Rill marks, caused by the running of drainage water
over inclined surfaces of mud and clay after recession of the
tide. These are often so complicated as to simulate foliage.

(d) Shrinkage cracks, produced by the drying and shrinkage
of muddy surfaces when left bare to be acted on by the sun and
air.

(e) Rain marks, or rounded pits produced by rain drops, or
washed surfaces produced by continuous rain, afterward covered
up and preserved by subsequent deposits. (See figures at end.)

These markings belong for the most part to shallow water and
to the vicinity of the shore and to tidal estuaries, They are often
of muci interest as indicating the conditions of deposit and the
changes which have taken place in these.

6. ARRANGEMENT OF Rocks ON THE LARGE SCALE.

With reference to this, the materials of the earth’s crust exist
in three different conditions:—(1) The Stratified; (2) The
Massive or Unstratified ; (3) The Vein-formed, The rocks of
the second and third classes are however subordinate to those of
the first, which vastly predominate in those parts of the earth
open to our inspection. We may therefore consider first and
principally the Stratified rocks. (Fig. 4).

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All ordinary aqueous or sedimentary rocks are stratified, or
arranged ir beds more or less nearly, when undisturbed, approach-
ing to a ho.izontal position.

A Lamina or Layer is the thinnest sheet into which a strati-
fied rock is divisible.

A Stratum or Bed is of greater thickness, or may consist of
several laminw—e. g. a bed of laminated sandstone consisting of
several layers,

A Formation consists of several beds deposited consecutively
and under similar general conditions. A formation may thus
include beds of rock of different kinds, though usually there is a
certain lithological similarity in the beds constituting a forma-

tion—e, g. the coal formation, which includes many beds of
sandstone, shale, coal, &c. (Fig. 5.)

si SsoIL
SY LOCAL ORIFT

LONITE

CREY SANDY SHALE
LIONITE

=| GREY & YELLOW
SANDY SHALE

IRONGTONE
OREY CLAY
CARBO!
OREY SANDSTONE

a LICNITE
SANDY GLAY
IRONSTONG
CARBONADEOUS SHALE
LIGNITE

OREY SANDY CLAY

Oa LICNITE
il SANDY CLAY

LIGNITE

GREY SANDY Gay
WITH ROOTS

Fig. 5.—Section of Lignite Tertiary formation, west of Manitoba.
The whole of the beds shown, except the soil and drift,
belong to one formation, though differing in mineral charac-
ters. Some of them, as the shale beds, are laminated. (G. M.
Dawson.)

A System or Group of Formations includes all the formations
of one of the larger geological periods—e. g. the carboniferous
system, which includes with the coal formation other formations
belonging to the same great geological period.

Inasmuch as formations and systems of formations imply the
lapse of time, they may also be designated by terms relating to
time. Thus we may speak of the carboniferous period, the coal-
formation epoch.

The term Seam is often used by miners for beds of useful
minerals; and when such beds are considerably inclined, they
are sometimes called veins, though not of the nature of true veins.

7. JoINts AND SLATY CLEAVAGE,

These appearances are important, because it is necessary to
distinguish them from planes of bedding.

Joints are planes of division cutting beds at various angles,
though usually approaching to verticul. They.often divide the
bed into oblique-angled blocks by the intersection of two sets of
cleavage planes; and when the cleavage planes of one set are
close together they often simulate true bedding. Joints some-
times facilitate the operations of the quarryman by enabling
blocks of stone to be more readily detached ; but when numerous
they injure stones otherwise useful.

When joints occur in beds of igneous rock they sometimes give
origin to a columnar structure, as in beds of basalt.

Joints are often slickensided, that is they have their surfaces
polished by friction which has occurred during movements of the
beds.

Joints are sometimes widened into fissures, which being filled
with foreign matter, constitute veins. The joints of rocks thus
connect themselves with the vein-condition afterwards to be
noticed,

Jointed structure sometimes weakens otherwise enduring rocks
so as to permit them to be worn into ravines and valleys.

Slaty structure is a lamination not caused by original deposi-
tion but by pressure subsequently exercised, whereby plates of
mica and other flat bodies present in the material, may be induced
to assume positions parallel to the plane of pressure. Such slaty
structure or slaty cleavage has been effected in many regions over

great thicknesses of beds, and while it is of practical importance
as giving the best roofing slates, it is somewhat puzzling to geolo-
gists as masking the true bedding. This can however usually
be ascertained by noticing the bands of colour and structure
which represent the original planes of deposit. In some cases
the planes of bedding and of cleavage coincide, but in very many
they are altogether different.

8. INotInED Position or Bens.

Aqueous strata have been originally deposited in a position
approaching to horizontality. The only exceptions to this are
where these beds have been uniformly disposed over uneven or
inclined surfaces, or where material has been washed over the
edge of a bank, giving rise to oblique stratification or false bed-
ding. Movements of’ the crust of the earth, and especially move-
ments of folding or bending which have apparently arisen from
the shrinkage of the mass of the earth as compared with its
crust, have however caused the originally horizontal beds to
assume various degrees of inclination, Aqueous erosion has
further caused the broken edges of bent strata to protrude at the
surface. The degree and direction of such inclination afford
most valuable data for ascertaining the relative positions and
ages of beds. The most important facts of this kind are the
following:— (Fig. 6.)

: SN
RR

Whi

4 QO .

a i) a 4

Fig. 6—Inclined position of rocks. Beds of slate (a), and iron
ore (+) dipping to the northward at an angle of 41°.

(a) Dip, or the angle of inclination to the horizon as measured
by the clinometer.

(b) Direction of dip as ascertained by the compass.

(d) Outcrop, or the line of intersection of the plane of the
bed with the surface of the country. On perfectly level ground
this is of course identical with the strike. Otherwise it is diffe-
rent,

ie weecsaecc nie

Observations of these, facts can be made in natural exposures,
as cliffs, shores, &c., in artificial exposures, as quarries, cuttings,
mines, &c. The harder rocks usually project in ridges and the
softer ure cut into hollows. Hence the lines of ridges and val.
leys often form very useful guides in tracing the outcrops of beds.
The harder rocks are also more likely to crop out at the surface
than those which are softer, and the latter are more liable to lie
in low ground and to be covered with soil,

A line drawn across the strike of a series of beds gives a sec-
tion of those beds, and in proceeding along such a line in the
direction toward which the beds dip we obtain an ascending
series. In the opposite direction we obtain a descending series.
Thus we can ascend or descend geologically in proceeding along
the surface of the ground, and geological ascent and descent do
not coincide with topographical, except where the beds are hori-
zontal or nearly so.

The thickness of beds is always measured at right angles to
their dip. For ordinary purposes it may be assumed that the
thickness is equal to ,'; of the distance across the outcrop at 5°
of inclination, and so on for every additional 5°.

When we follow a series of beds in ascending or descending
order, we at length arrive at a line in which their dip changes
to the opposite direction. When this takes place in the descend-
ing series it constitutes an anticlinal line or axis, sometimes
called an anticline. When it takes place in the ascending series
it constitutes a synclinal line or syncline.

When the anticlinal and synclinal axes are not horizontal, or
when the surface of the country is inclined, the beds may be seen
at the surface to bend around the ends of the anticlinals or syn-
clinals, so that on a map these appear as more or less abrupt
bends or loops of the strata.

In those regions where the beds have been slightly inclined,
the anticlinals and synclinals are low and wide ; but in disturbed

districts the folds are often very abrupt, causing the beds to
approach to verticality, and in some places to be overturned. In
such cases also the anticlinals or synclinals are sometimes very
steep on one side and less so on the other, and they are not in-
frequently accompanied with minor flexures and foldings of the
beds as well as with fractures or dislocations. In such disturbed
districts great caution is requisite lest abruptly folded and re-

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series, and lest overturned beds should be regarded as in their
(Figs. 7, 8, 9.)

natural positions.

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Fig. 9.—Beds of Limestone, Sandstone and Shale of Lower Carbon-
iferous age in a vertical position. Smith’s Island, Cape

Breton.
9, FAULTS.

When movements of beds have been accompanied with frac-
ture and slipping of the beds up or down, faulting or discontin-
uity of beds is produced.

Faults traversing inclined beds may displace them laterally as
well as vertically. The vertical displacement is sometimes des-
ignated by the term slide, the lateral displacement by the term
heave. A downthrow is said to take place on that side toward
which the beds are sunken, and an upthrow on that side toward
which they have risen. When the plane of a fault is inclined,
the inclination is usually called by miners its ‘‘ hade,” and is
measured from a vertical plane. The downthrow is almost al-
ways found to have occurred on the side toward which the plane
of fault inclines. When the contrary occurs the fault is said to
be reversed. This fact is often of great importance in estimating
the effects of faults. (Fig. 10.)

In observing faults, the facts to be noticed are the directions of
the planes of fracture, their hade and the amount and direction
of movement, with its effect on the beds traversed. When these
facts are obtained, all the effects of the dislocation can be readily
worked out, though, when several lines of fault cross the same
beds, the appearances are often very deceptive, leading to incor-
rect estimates of the thickness and number of the beds.

GREY SANDY CLAY

Fig. 10.—Fault, Lignite Tertiary series, Porcupine Creek, N. W. T.
(G. M. Dawson.) The bed of lignite (a) has been thrown
down, and has been removed by denudation from the
other side of the fault.

As the inequalities caused by faulting have usually been
rounded or smoothed off, and the line of a fault is often a weak
place where the rocks have been worn down and covered with
debris, fuults can very rarely be distinctly seen, and their nature

and direction can usually be ascertained only by inference from
the dislocation observed in the beds on their opposite sides,
They are very numerous in disturbed districts, and there are
often two or more sets of them crossing the beds in different
directions. In most cases, however, the amount of movement
which they produce is not great.

10. UNCONFORMABILITY.

When one series of beds has been disturbed and another de-
posited upon the upturned edges of the first, the upper series is
said to rest unconformably on the lower. This indicates not
merely a difference of age but an interval of time between the
dates of the two series. It often happens also that the edges

Fig. 11.—Unconformable superposition of (c) Silurian beds on (d)
Cambrian, and of the latter on (a) Eozoic. West of Scot-
land. (After Murchison.)

of the lower series show evidences of great erosion, or that
the beds of the lower series have been hardened and altered
before the deposition of the upper. <A false or simulated want
of conformity occurs when a bed has been cut unequally by water
before the next bed is deposited. When cong] merates or coarse
sandstones rest upon finer beds such apparent unconformity is
often produced. (Fig. 11.)

11. DENUDATION.

This is the removal of matter by atmospheric or aqueous ero-
sion. It has already been referred to as a source of the materials
of aqueous deposits. We must now consider it as concerned in
giving relief to the surface of the earth. That denudation has
taken place to a great extent may be inferred from such facts as
the following: The projection of hard beds and massive rocks in
consequence of the removal of softer material from around them ;
the existence of synclinal elevations in consequence of the erosion
of anticlinals which once were higher but must have been more
perishable owing to their fissured condition; the planing away
to a low level of rocks which testify by their dips or by the
existence of extensive faults that they once rose to much greater
height and were very uneven; the cutting of deep ravines
through table lands, and the quantity of stones, gravel, sand,
and other detritus of older formations, employed in the building
up of those which are newer. (Fig. 12.)

n°
Fatt
Tatu

Fig. 12.—Denudation of horizontal beds, Great Valley, N. W. T.
(G. M. Dawson.)

Geological observation has shown that the inequalities of the
earth’s surface are due to denudation more than to any other
cause.

It has been estimated that the areas drained by the rivers of
our continents are losing by denudation at rates varying from 1
foot in 1500 years to 1 foot in 6000 years. At these rates, were
no counteracting elevation to take place, our continents would be
levelled with the sea in from four millions to nine millions of
years,

12. Massive Rooks.

These are in almost all cases of igneons origin, and can be
readily distinguished both by their mineral character and their
mode of occurrence, from the stratified rocks. Such irregular
masses may represent either (1) the remains of the bases of old
voleanic cones, the looser parts of which have been swept away ;
or (2) exotic or intrusive materials ejected among other rocks
from beneath ; or (3) portions of the aqueous crust so much
altered that their stratification has been obliterated.

If the stratified rocks have been altered at their contact with
igneous masses, or are penetrated by veins proceeding from them,
we know that the masses are newer than the beds. On the other
hand, if the massive rocks have been eroded before the deposi-
tion of the beds, if the latter are unaltered, and if they contain
debris derived from the massive rocks, we know that these are

older. (Fig. 4.)

13. VEIN-FORMED Rocks.

The most common veins are fissures filled with material intro-
duced either in a molten state or in aqueous solution.

Igneous veins or dykes are often of great size, and exten
through the stratified rocks for long distances. They are filled
with some of the kinds of igneous rock; sometimes present a
jointed structure at right angles to their sides; often have the
surface in contact with the adjacent rock of different texture
from the interior ; and have often, by their heat, produced con-
siderable alteration in the adjacent rock. They are especially
numerous in the vicinity of igneous masses and of volcanic foci
ancient or modern. (Fig. 13.)

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f
"|
i
1,
H
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Fig. 13—Igneous dykes or veins, extension reservoir, Montreal.
(a) Felspathic dyke traversing beds of limestone.
(8) Floor or horizontal vein of Dolerite cutting (a).
(c) Thick dyke of Felsite cutting (4). (d) Inclined
dykes of Dolerite cutting all the others.

Aqueous veins, which are also often mineral veins, are usually
filled with crystalline minerals deposited in them by water.
They often present a laminated appearance, owing to the deposi-
tion of successive coats of matter in the walls of the vein. Occa-
sionally the walls of veins present margins or “ selyages” con-
sisting of decomposed rock or decomposed veinstone.

In the case of mineral veins, the mass filling the vein is called
gangue or veinstone, as distinguished from the ore associated

with it. (Fig. 14.)

b a :

\
il

Fig. 14,.—Metallic veins near the contact of slate and granite. (After
Von Cotta.) (a) Fissure vein. (b) Horizontal or bedded
vein sending off a branch (e). (ce) Contact vein at the
junction of the two formations. (d) Lenticular or inter-
rupted veins, sometimes called by miners “ pockets.”

Veins are often very irregular in their forms. This arises not
only from the original irregularity of cracks traversing rocks,
but from subsequent shifts of the containing walls, from the de-

SETMVANUON BAe rian]
bite 2.) > bs WN Y peony

tachment of loose pieces or “ horses’’ from the sides, and from
erosion of the walls by subterranean waters. They also differ
‘very much in their contents in passing from one kind of rock
into another, and are often decomposed and changed by atmos-
pheric action at their outcrops.

There is reason to believe that some veins have been filled
simultaneously with their opening, so that they have never
actually been open fissures. Such veins, which present many
peculiar appearances, are called segregation veins.

14. CHronoLoay or BeEps.

Superposition.—The great leading fact as to the ages of aque-
ous deposits is that the upper of two beds is necessarily the
newer. Wherever therefore the actual superposition of beds can
be ascertained, there can be no doubt as to their relative ages.
In mines and borings, and in cliffs and quarries, we can thus
easily ascertain the ages of the beds exposed. In the case of
inclined beds this is equally obvious as in those which are hori-
zontal. In these however we must be careful not to be misled
by overturns and by beds repeated by faults.

No one exposure, however, can show anything more than a
limited portion of the series of rocks occurring in any district of
considerable extent. Hence in extending the results of our
observations it is necessary to have recourse to other data.

Tracing of beds.—Having ascertained the sequence of beds in
one locality, we endeavour to trace them along their outcrops.
We thus bring them into relation with other beds not seen in
the original exposure.

Mineral character.—Where the tracing of the beds fails, we
have to compare them in different sections, and to endeavour to
recognize them by their mineral character—a succession of like
beds in two not very distant sections giving us fair evidence of
identity. Here however we must remember that in tracing any
given bed for a long distance, it cannot be expected to retain
precisely the same character, but may be represented by some
different material.

Fossil remains.—W hen we can obtain from any of the beds in
question fossi] organic remains, these afford us a new means of
testing identity of age. Experience has shown that in the
course of the earth’s history the facies of animal and vegetable
life has been constantly changing, so that the fossils of one for-

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mation are different from those of another. When we have in
any one locality ascertained this succession, we are safe in apply-
ing it to others, The evidence of fossils is thus at present held
to be one of the best criteria for the ages of stratified rocks,

In employing fossils as evidence of age, we have however to
bear in mind certain necessary precautions, There are other
differences than those of age; as for example, the difference be-
tween animals of the sea, of freshwater and of the land; of
different depths in the sea, and of different climates, It is neces-
sary, therefore, to compare animals or plants of like habitat and
conditions of existence. It is farther to be observed that certain
forms of life have been of longer duration in geological time than
others, and therefore do not so definitely mark the lapse of time.
Again, certain forms of animal or vegetable life may have begun
earlier or continued later in one locality than in others. On
these acccounts the evidence of fossils is more certain with refer-
ence to the greater geological periods than with reference to the
minor subdivisions of these.

15. GroLogicAL MAps AND SECTIONS.

The facts and generalizations obtained on the above grounds
are represented to the eye on maps and sections, On the former
are indicated by spots or lines of colour or by differences of
shading the different formations and their precise boundaries as
far as ascertained. To these may be added marks indicating
dip and strike and other arrangements, (Fig. 15.)

a 4&4 /e d é f ¥
Fig. 15.—Marks used in mapping. (a) Horizontal beds. (6) In-

clined. (c) Undulating. (d) Contorted. (e) Vertical.
(/) Anticlinal. (g) Synclinal.

While maps exhibit the horizontal distribution of formations,
sections show more clearly the relations of age and superposition.
Lines of section observed on the ground may in the first instance
afford materials for the construction of a map, and when a map
has been drawn these lines may be marked on it, and the sections
along these lines may be drawn to accompany it. Such sections
are usually named horizontal sections. But vertical sections
may be obtained in shafts and borings, or may be constructed
with the aid of the horizontal sections.

Ill. PALAZONTOLOGY.
1. PRESERVATION OF ORGANIC REMAINS,

This depends in the first instance on the accidental imbedding
of animals and plants or of portions of them, in deposits in pro-
cess of formation, or on the accumulation of remains of animals
and plants on the surfaces on which they live, as for example of
shells and corals on the sea bottom, or of vegetable matter in
bogs and swamps. In one or other of these ways most aqueous
deposits become more or less charged with organic remains,
These are sometimes entire and sometimes fragmentary, and as
already stated some beds contain so great abundance of organic
fragments that they may be regarded as organic rocks. Often,
however, the presence of organic fragments can be detected only
by the lens or the microscope. (Figs. 16, 17.)
> * nad TAG

py ff
fel

Wy) LY
i s)

| STi
Fig. 16.—Fine grained Trenton limestone, Montreal, showing organic
fragments x 10.

fe
hy

fi!
iit ri

Fig. 17.—Chazy Limestone, Island of Montreal, showing fragments of
shells and Stenopora x 10.

ee TS

Bits eneraminetrir aia

Organic remains may occur in an unchanged condition or only
more or less altered by decay. This is often the case with such
enduring substances as shells, corals, bones and wood, especially
in the more recent deposits, in which such remains occur little
modified or perhaps only slightly changed by partial decay of
their more perishable parts, as for instance of the animal matter
of bones. In the older formations, however, organic remains are

usually found in a more or less mineralized condition, in which

their original substance has been wholly or in part replaced by
mineral matter, or has been chemically changed. The more im-
portant of these changes are the following :—

(a) Infiltration of mineral matter which has penetrated the
pores of the fossil in a state of solution. Thus the pores of fossil
wood are often filled with calcite, quartz, oxide of iron or sulphide
of iron, while the woody walls of the cells and vessels remain in
a carbonized state. (Fig. 18.) Bones, shells and corals in like
manner have their cavities filled with mineral matter, and are
rendered hard and heavy thereby. In the sea bottom the filling
material is not infrequently composed of Glauconite or other
hydrous silicates, (Fig. 19.) We sometimes find on microscople
examination that even cavities so small as those of vegetable
cells and vessels have been filled with successive coats of different
kinds of mineral mutter,

Fig."18.—Discigerus tissue (a, 4), and Scalariform tissue (¢) from car-
bonized plants of the Devonian system, highly magnified.

(b) Organic matters may he entirely replaced by mineral sub-
stances. In this case the cavities and pores have been first filled,
and then, the walls or solid parts being removed by decay or
solution, mineral matter either similar to that filling the cavities
or differing in colour or composition, has been introduced. Silici-
fied wood and silicified corals often occur in this condition. In
the case of corals and similar calcareous structures included in
limestone, it sometimes happens that the walls of the corals are

silicified while the cells are filled with limestone, Fossils thus
preserved often appear with great distinctness projecting from
the weathered surfaces of the containing rock, (Fig. 20.) In
the case of silicified wood, it sometimes happens that the cavities
of the fibres have been filled with silica and the wood has been
afterwards removed by decay, leaving the casts of the tubular
fibres as a loose filamentous substance. The more important of
the foregoing modes of preservation are represented in Fig, 21.

Hitt td

Fig. 19.—Joint of a Crinoid having the pores filled with a hydrous
silicate allied to Glauconite. Upper Silurian, New Bruns-
wick, Magnified.

Fig. 20.—Silicified corals, Petraia pygmea,
and crinoidal joints weathered
out on a rock surface. (After
Billings.)

ULE
Vn

o
-
<
-
=

wavrt*=wzoweas

Fig. 21.—Sections of part of a cell of a Tabulate coral in different:
states of preservation.
(a) Cell-wall calcite, cavity empty.
(d) Cell-wall calcite, cavity filled with the same.
(c) Cell-wall calcite, cavity filled with silica or a silicate.
(42) Cell-wall replaced by silica, cavity filled with calcite,
(e) Cell-wall replaced by silica, cavity filled with silica.

(c) The substance of organic remains may be wholly removed,
leaving mere moulds or impressions of their external forms, or
perhaps moulds of the external forms and casts of the interiors.
This frequently occurs on the surfaces of rocks, where for ex-
ample calcareous fossils have been weathered out from a harder
matrix, but it also occurs in the interior of porous beds, owing to
the solution of the fossils by percolating waters. In the case of
fossils in this state, it is always necessary to consider whether the
impression observed is that of the true exterior surface, of an
inner layer, or of an interior cavity.

(d) The cavities left by fossils which have
decayed may be filled with clay, sand or other
foreign matter, and this becoming subse-
quently hardened into stone may constitute a
cast of the fossils. Trunks of trees, roots,
&c., are often preserved in this way, appear-
ing as stony casts, often with the outer bark
of the plant forming a carbonaceous coating
on their surfaces. (Fig. 22.)

Fig. 22.—Trunk of Sigillaria represented by a
sandstone cast of the interior of the bark.
Coal formation of Nova Scotia. Reduced.

Fossils preserved in the two first modes usually show more or
less of their minute structures under the microscope. These
may be observed, (1) By breaking off small splinters or flakes
and examining them either as opaque or as transparent objects.
(2) By treating the material witi acids, so as to dissolve out
the mineral matters or portionsof them. This method is applic-
able to some fossil woods, silicified corals, &. (3) By grinding
thin sections, These are first polished on one face, then at-
tached to glass slips by a transparent cement or Canada balsam,
and ground until they become so thin as to be translucent.

Ichnites or fossil footprints and similar markings constitute a
peculiar and sometimes interesting kind of fossils, Animals
walking over muddy shores may leave impressions, which being
partially hardened by the air and sun, may not be obliterated
by the succeeding deposits of sand or mud. Once so covered
up, they ren ain for an indefinite time, and if the beds be har-

dened into stone, the footprints appear distinctly as the layers
are removed by the quarrymen. In this way the footprints of
some land animals, not known to us by other remains, have been
preserved, and important information has been obtained as to
their affinities and habits. (fig. 23.)

l COE,
Wii] ff, ~eE
Lihipypliyy V 4 -
Myf, | Ld
YY “WY yi,
ly Wi

Fig. 23.—Footprints of a Batrachian (Sauropus). Coal-field of Cape
Breton.

Not only land animals, but aquatic creatures, as fishes, crus-
taceans, worms, and mollusks, have left impressions and trails on
the surfaces of beds, and these though less definite than the foot-
prints of land animals, are of some importance as fossils. Such
impressions have sometimes been mistaken for fossil plants; but
they can be distinguished by the absence of carbonaceous matter,
by their close connection with the substance of the containing
beds, by their being in relief on the under side of the beds, and
by their forms. (Fig. 24.)

The geological observer in examining any section or exposure
of rocks, while noting all the facts respecting stratigraphical
arrangement and relations, carefully collects the fossils of each
bed, and labels them in such a manner that their order of suc-
cession can be preserved. The study of these fossils may be
expected to afford important information respecting the age and
conditions of deposition of the beds, Should the observer not

Se ee ner RT Pa ee

possess the special knowledge necessary to interpret the fossils
obtained, he has recourse to palwontological specialists, either
experienced in the fossils of the formation in question, or of the
groups of animals or plants represented in the collections.

Fig. 24.—Tracks probably of a Crustacean (Rusichnites). Coal-
formation of Cape Breton.

The most abundant and characteristic fossils available to the

paleontologist ere those of aquatic animals, having hard shells,

“fl crusts or cells. Thus practically the most important elementary

knowledge of the study of fossils is that relating to the characters

of invertebrate animals, and especially those of the sea. The

i student should therefore have some familiarity with this subject,

and should have for reference some good zoological text-book,

and if possible some work on the special paleontology of the
districts or formations he is studying.

In some geological formations, especially the middle and newer
members of the geological series, a knowledge of vertebrate
\ animals becomes important ; while in others, as the coal-forma-
tion, an acquaintance with fossil plants is necessary.

The following tables indicate the groups of animals and plants
most important to be known in connection with the study of
fossils :-—

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IV. HISTORICAL GEOLOGY.

The application of the facts and principles of lithology, strati-
graphy and paleontology to any given district, enables us to
work out the geological succession of formations or geological
history of the district in question, including not only the physical
changes but the changes in living beings that may have occurred.
The comparison and grouping of such local results enables us at
length to frame a table or chart of the geological history of the
whole earth. This we shall now proceed to construct, beginning
with the oldest formations, and giving what may be regarded as
typical examples of each from those regions in which it may be
best developed and most fully studied,

The whole geological history of the earth may be included in
four great Periods, the names of which have been based on the
progress of animal life. They are, beginning with the oldest—

1. The Eozoic Period, or that of Protozoa.

2. The Paleozoic Period, or that of Invertebrate animals,

3. The Mesozoic Period, or that of Reptiles.

4. The Kainozoic Period, or that of Mammals and of Man.

They are farther subdivided into Ages, or if we regard the
rocks themselves rather than the time occupied in their deposi-
tion, into Systems of Formations. These are represented in
the following table, beginning as before with the oldest :

Laurentian
Ni .
WOviacivadis
Kozo | Huronian.

( Cambrian.
| Siluro-Cambrian.
} Silurian,
1 Krian or Devonian,
Carboniferous,
{ Permian.
Triassic.
MESOZOIC .... | sari

PALAOZOIC...

Cretaceous.

Eocene.
Miocene.
Karnozoic ...2 Pliocene.
Pleistocene.
Modern.

Si a a re ae,

4 sre

In noticing these systems of formations and their subdivisions
in detail, we shall begin as far as possible with Canadian repre-
sentatives of them, and shall then notice their foreign equivalents
and characteristic fossils ; concluding the notice of each system
with a statement of its geographical distribution, Since Canada
embraces about half the area of North America, and includes
portions of all the geological formations of the continent, we
shall in most cases be able to obtain within its limits typical
examples of rocks and fossils; and when these fail, shall have
recourse to other regions.

EOZOIC PERIOD.
I. LAURENTIAN System.

1. Lower Laurentian. In Canada—Orthoclase gneiss of
Trembling Mountain (Logan), Ottawa gneiss (Geol. Survey),
lower part of Lower Laurentian of Logan. European equivalents
—Bogian gneiss, Ur gneiss, Lewisian gneiss. Consists mostly
so fur as known of beds of orthoclase gneiss destitute of fossils,
constituting the “ fundamental gneiss’’ of some geologists. |

Fig. 25.—Section showing the mode of occurrence of Zozoon in Middle
Laurentian at St. Pierre. (a) Gneiss; (+) Limestone ;
(c) Diorite and Gneiss.

2. Middle Laurentian. In Canada—Qneiss, diorite, lime-
stone, pyroxene rock, &c., of Grenville, Petite Nation, &c.,
being the upper part of the Lower Laurentian of Logan.
Kuropean equivalents—Ur gneiss in part, Lewisian gneiss in
part, Etage A of Bohemia in part, Dimetian of Wales ? Gneiss
and crystalline limestone of Brittany.

Fossils.—Fozoon Canadense, and graphitised plants. (Figures of

many of the fossils named in this and following pages will be found
in the plates at the end.)

3. Upper Laurentian. In Canada—Labradorite and Anor-
thosite series of the Ottawa district, &e. European equivalents
—Etage A of Bohemia in part, Dimetian of Wales? Norite
formation of Scandinavia. No fossils known.

Distribution in Canada, &c. These formations constitute an
extensive angular belt extending south-westward, north of the
St. Lawrence valley, from Labrador to the Western coast of Lake
Superior and thence north-west to the Arctic ocean, At the
Thousand Islands this belt is connected with an extensive penin-
sula in the State of New York. Minor areas protrude through
the Paleozoic rocks in Newfoundland, New Brunswick, and the

Atlantic coast of the United States, and also probably in the
mountainous belt fringing the Pacific coast. Iron ores, Apatite

and Graphite abound in the Laurentian.

Il. Huronian System.

1. Lower Huronian. In Canada—Chloritic slate, jasper
conglomerate, slate conglomerate, quartzite, limestone and bedded
diorite of Georgian Bay. Similar rocks in Newfoundland, New

Brunswick and possibly also in the Hastern Townships of

Quebec. European equivalents — Urschiefer of Scandinavia,
Ktage A of Bohemia and Pebidian of Wales (Hicks).

Fossil.—Eozoon Bavaricum, Gumbel.

2. Upper Huronian, In Canada—-Conglomerates, slates and
grits of Kastern Newfoundland ; Kewenian group of Lake Supe-
rior. European equivalents not certainly known.

Fossils.— Aspidella Terra-novica, Billings ; Arenicolites.

Distribution. —The Huronian is extensively developed on the
north side of Lake Huron and south and west of Lake Superior.
It occurs also in Newfoundland and New Brunswick, and prob-
ably in various parts of eastern Quebee and the Atlantic States.
It contains extensive deposits of iron, copper and silver.

Notre.—The precise relations of the Hastings group of Hastern
Ontario, and various other groups of altered rocks resembling it in
mineral character, with the Huronian, are not yet well understood.

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57
PALASOZOIC PERIOD.

I. CAMBRIAN SysTEM.

1. Lower Cambrian. In Canada—Quartzite and slate of the
Atlantic coast of Nova Scotia, with Astropolithon, Scolithus and
Eophyton. European equivalents—Longmynd series of EKng-

land, Harlech grits and Llanberris shales of Wales, Etage B of

Bohemia, Eophyton shale of Scandinavia.
Fossils.—_Sponges, Worms, Polyzoa, Brachiopoda, Pteropoda, Trilo-
bites, appear first in the Lower Cambrian.

2. Middle Cambrian, In Canada—Acadian group of New
Brunswick and Newfoundl:.ud, Lower Potsdam in part of Lower
St. Lawrence. EKuropean equivalents—Menevian slates and flags
of Wales, Lower alum slates of Sweden, Htage C of Bohemia.

Fossils.—Paradoxides, Conocoryphe and other Trilobites character-
istic. Also Lingulella, Orthis, Discina, Focystites, &c.

3. Upper Cambrian. In Canada—Potsdam sandstone and
lower Calciferous of Quebec and Ontario, fossiliferous Cam-
brian of Miré, Cape Breton. European equivalents—Lingula
flegs and Tremadoce slates and sandstones of Great Britain ;
Upper alum slates of Sweden.

Fossils.—Scolithus, Lingula, Dikelocephalus and Protichnites charac-
terize the typical Potsdam. Various Corals, Crinoids, Lamellibranchs,
Heteropods, Gasteropods and Cephalopods occur in the upper member,
which shows transition to the next age.

Distribution.—The Lower Cambrian is best developed on the
Atlantic coast of Nova Scotia, where it constitutes the gold-
bearing series. The Middle Cambrian occurs in eastern New-
foundland and southern New Brunswick. The Potsdam is ex-
tansively developed in the western part of the Proviuce of Quebec
«4d in New York, where it often rests directly on the Laurentian.

II. SiriuRo-cAMBRIAN SYSTEM.

(Lower Silurian of Murchison.)

1. Quebec Series. In Canada—Shales, limestones and sand-
stones of Point Levis, and the south side of the Lower St. Law-
rence, In the United States a belt extending southward through
Vermont and New Hampshire. European equivalents—Llandeilo

series in part; Arenig (Skiddaw and Borrowdale) of Kngland ;
Etage D1, Bohemia; Lower Graptolithic slates of Scandinavia,

Fossils.—Graptolites of Genera Graptolithus, Phyllograptus, Dendro-
graptus, Diplograptus, Dictyonema, &c. Trilobites of Genera Dikeloce-
phalus, Agnosius, Arionellus, Bathyurus, &c., Land plants? Protannularia
of Skiddaw series.

and slate of Hastings series, Hog Lake, Ontario.

2. Trenton Series, In Canada—Chazy, Black River and
Trenton limestones of Quebec and Ontario. Corresponding
rocks of the New York series. Huropean equivalents—Bala
Formation of England and Wales; Etage D2 of Bohemia; Regio
©, or Oeland limestone of Scandinavia; Graptolite and Calymenc
slates of Franee—Second Fauna of Barrande. .

Fossils —Rich invertebrate Fauna of Corals, Crinoids, Brachiopods,
Lamellibranchiates, Gasteropods, Cephalopods and Crustaceans. The
following are very characteristic in Canada—WStenopora sibrosa, S. Petro-
politana, Glyptocrinus ramulosus, Columnaria alveolata, Tetradium fibra-
tum, Ptilodietya acuta, Strophomena alternata, Leptaena sericea, Orthis
lynx, Lingula quadrata, Cyrtodonta Huronensis, Murchisonia bellicincia,
Pleurotomaria subconica, Conularia Trentonensis, Asaphus mégistos, Tri-
nucleus concentricus. ,

In Nova Scotia and New Brunswick the Trenton and Quebec
series appear to be represented by the Graptolite slates of North-
ern New Brunswick, and by the felsites, agglomerates, slates, Xe.
of the Cobequid Mountains, &e. in Nova Scotia, which have been
named the Cobequid series, They resemble in mineral character
the Borrowdale series of England.

3. Hudson River Series. In Canada—Utica shale of the St.
Lawrence Valley, shales, coarse limestones and xandstones over- —
lying the Utica in various parts of Ontario and Quebec, and
extending southward into the United States. European equiva-
lents—Caradoc sandstones and shale. Regio D of Seandinavia ;
Etages D3, D4, Bohemia.

Fossils—Continuation of Invertebrate Fauna of Trenton in part,
with some new types, as Favistella stellata, Halysites gracilis, Pterinea
demissa, Asaphus Canadensis, Triarthrus Beckii and 7. spinosus. Craptolites
abound in some parts of the Utica, especially @. pristis, G. bicornis and
GQ. ramosus. Warliest certainly known Land plants — Protostigma,

Annularia, Sphenophyllum, Eopteris.

Distribution. —Formations of this age oecur in patches along
the northern coast of the Gulf and River St. Lawrence, on the
north side of Anticosti and on the south side of the St. Lawrence
‘rom Gaspe. From Bay St. Paul upward, they occupy both sides
of the St. Lawrence and the Valley of the Lower Ottawa. as far
up as the Thousand Islands, Westward of this they form a broad
belt extending across Ontario from Lake Ontario to Georgian Bay,
They occur in the Islands of Georgian Bay and the North Chan-
nel, and at River St. Mary cross over into the United States.
They reappear in the Valley of the Red River.

Lil. Sipurtan System.
(Upper Silurian of Murchison. )

1. Medina Series. In Canada—Sandstones of the West end
of Lake Ontario and extending thence into the United States.
Lower part of Anticosti series, European equivalents—Llan-
dovery formation of Wales or beds of passage, including the
Mayhill sandstone. Ktage E1 Bohemia.

Fossils. —The trails known as Arthrophycus, and Lingula Cuneata are

characteristic.

2. Niagara Series. In Canada-——Clinton and Niagara lime-
stone of Ontario, and their extension southward into the United
States. Lower Arisaig and New Canaan slates of Nova Scotia;
Upper Silurian limestones and slates of Northern New Bruns-
wick and Gaspe in part. HKuropean equivalents—Wenlock lime-
stone and shale of England, Ktage K2 of Bohemia.

Fossils —The Niagara limestone contains a rich marine tauna:

Astylospongia praemorsa, Stromatopora concentrica, and Corals, &c. of the
genera Favosites, Halysites, Heliolites, Dictyonema; Crinoids, as Stephano-
crinus and Caryocrinus ; Mollusks, as Strophomena rugosa, Pentamerus,
Spirvfer Niagarensis. Trilobites of genera Dalmania, Lichas, Calymene,
and /llaenus, are characteristic. Glyptodendron of the Clinton is probably
a Lycopodiaceous plant.

\
WN

AY \\\ ANNO at i yu
. a a

, \\\ ea

Fig. 30.—Silurian shales affected with slaty sleavage, Matapedia River.

3. Salina Series, In Canada—Shales, marls, dolomites and
rock salt of Goderich in Ontario. This is » local series confined
to the interior basin of North America, and marking a period of
elevation and dry climate with deserts and salt lakes. The
Guelph or the Galt limestone of Ontario is a transition deposit
between this and the Niagara. The fossils are few—Megalomus
Canadensis, a large lamellibranchiate, is characteristic of the Galt
limestone, There are also species of Murchisonia, Cyclonema, &e.

4. Helderberg Group. In Canada—Limestone of St. Helen’s
Island, Montreal ; Oriskany, &c., of Ontario; Cape Gaspe lime-
stone; Upper Arisaig series, Nova Scotia. European equivalents
—Ludlow Series of England; Etage F, G, of Bohemia.

Fossils—Pentamerus galeatus, P. pseudo-galeatus, Rhynchonella ventri-
cosa. Species of Merista, Chonetes, Eatonia and Stricklandinia, Tentaculites
and Eurypterus, are characteristic. Fossil plants of genus J’silophyton
occur. Earliest fossil fishes—Placoganoids and Selachians.

Distribution—The Silurian rocks are well developed in the
district extending north-westward from the Niagara river to Lake
Huron. They occupy a large area in Quebec and Northern New
Brunswick, extending S.W. from Gaspe and the Bay de Chaleur;
and isolated areas occur in Nova Scotia and Southern New
Brunswick.

IV. Ertan System.
(Devorian of English Geologists).

1. Corniferous Series—Corniferous limestone and associated
sandstones in Ontario, Lower Gaspe sandstones. Huropean equi-
valents—Plymouth and Linton groups of Devon; Kifel lime-
stones, spirifer sandstone of Germany; old red sandstone of
Scotland and West of England.

Fossils—Placoganoid and Ganoid fishes abound. Abundant corals
of genera Favosites, Heliophyllum, Eridophyllum, Cystiphyllum, Zaphrentis,
&c. Plants—Prototaxites Logani and Psilophyton princeps.

3. Hamilton Series—Hamilton shales of Western Ontario,
Middle part of Gaspe sandstones, Corduite shales of St. John
New Brunswick. European equivalents—Middle Devonian of
England and Scotland ; upper part of Kifel formation.

Fossils. —Spirifer mucronatus and Atrypa reticularis and aspera are
common, The genus Goniatites appears. Fishes of genera Dinichthys.
Trilobites of genus Phacops. Numerous fossil plants of the genera
Calamites, Lepidodendron, Psilophyton, Archaeopteris, Cordaites, &c. The
earliest insects, (Platephemera, &c.) appear in the St. John shales.
Karliest Decapods, (2alaeopalemon).

4, Chemung Series. In Canadu—Shales &e. of Kettle Point
Lake Huron, Upper Gaspe sandstone, Upper sandstone and con.
glomerate of St. John, New Brunswick. European equivalents
-—Upper old red sandstone of Scotland, Kiltorcan beds in Ire-
land, Petherwin group of Devon, Cypridina shale of Germany.

Fossils.—Many Lamellibranchiates of genera Pteronites, Avicula, &c.
Fishes of genus Holoptychius, Pterichthys, &c. Ferns of genus Archae-
opteris, Cyclopterie. &c.

Distribution. These rocks occupy the peninsula of Ontario
between Lakes Erie and Huron. They occur largely in the re-
gion south of Lake Erie and elsewhere in the United States.
They are extensively developed in Gaspe and the Bay de Chaleur
and also in Southern New Brunswick. In the maritime regions
however, last mentioned, the great limestones, so rich in corals in
Ontario, are wanting,

V. CARBONIFEROUS SYSTEM.

I. Horton Series, Lower Carboniferous Shales and Conglom-
erates, Horton Bluff, &c., in Nova Scotia, Equivalents in United
States—Vespertine group of Pennsylvania; Waverly sandstone
(in part), Ohio; Kinderhook and Marshall groups of Illinois and
Michigan ; lower or false coal measures of Virginia. European
equivalents—Tweedian group or Calciferous sandstones of Scot-
land ; Carboniferous shale and Coomhuala grits of Ireland ; Culm
formation of Germany, Graywacke of Vosges.

Fossils —Fishes of genera Rhadinichthys, Rhizodus, Acrolepis, Ctena-
canthus, &c. Footprints of earliest known Batrachians : Lepidodendron
corrugatum, Cyclopteris Acadica, Cordaites, &c.

2, Windsor Series. In Canada—ULower Carboniferous lime-
stones and gypsiferous series of Nova Scotia and New Brunswick.
Equivalents in United States—Burlington, Kekuk and Chester
lifmestones of Illinois. European equivalents—Old Mountain
or Carboniferous limestone of England ; Caleaire Condrusien of
France; Kohlen-kalkstein of Germany; Fusulina limestone of
Russia.

Fossils —Marine Invertebrates of genera, Fusulina, Lithostrotion, Cya-

thophyllum, Fenestella, Productus, Terebratula, Athyris, Spiryfer, Aviculo-
pecten, Macrodon, Conularia, Nautilus, Orthoceras, Phillipsia, &c.

3. Millstone grit. Canadian types—Suandstones and conglome-
rates between the Carboniferous limestones and the coal forma-
tion, in Nova Scotia and New Brunswick. In United States—
Seral conglomerate of Pennsylvania, Lower Carboniferous sand-
stone of Kentucky, Alabama and Virginia, Chester group of IIli-
noisin part. European equivalents—Millstone grit and Yoredale
rocks of England; Moor rock of Scotland ; Jungste Grauwacke
of the Hartz, Saxony and Silesia.

Fossils.—Plants similar to those of the Coal formation.

4, Coal Formation. In Canada—Productive coal measures
of Nova Scotia and New Brunswick. In United States—coal
formation of Pennsylvania, Ohio, Illinois and Michigan, repre-
sented in the west by marine limestones, &c. In Kurope—the
coal formations of Scotland, England, France, Germany, &c.

Fossils —Land plants of genera Araucarozylon, Sigillaria, Lepidoden-
dron and Calamites, and Ferns and allied plants. Fishes of genera
Pulaeoniscus, Rhizodus, Diplodus, Gyracanthus, §c¢. Batrachians of
genera Baphetes, Dendrerpeton, Hylonomus, Anthracosaurus, &c. Insects,
Miltepedes, Arachnidans and Decapod Crustaceans.

Distribution —In Canada the Carboniferous occupies con-
siderable areas in Nova Scotia and New Brunswick, and includes
the oxtensive and valuable coal fields of Cumberlaud, Pictou and
Cape Breton. Small areas of the Permo-carboniferous oceur
in the south of Prince Edward Island; and the Lower Carbon-
iferous, locally termed the Bonaventure formation, extends into
the east of Quebec. A limited area, including beds of' coal,
occurs in western Newfoundland. In the west, rocks of Carbon-
iferous age occur in the Rocky Mountains and in British Col-
umbia, but without beds of coal.

63
VI. PeERMIAN System.

1, Lower Permian, Canadian type—Permo cerponiferous red
sandstones of Prince Edward Islan and Eastern Nova Scotia.
In United States—Permian sandstones of Virginia and lime-
stones of Kansas and Nebraska. Upper Carboniferous beds of
Illinois, holding remains of reptiles. Huropean equivalents,
Lower Permian sandstones of England, Rotheligendes of Ger-
many, Lower Permian Sandstones and Limestones of Russia.

Fossils.—F or the most part generically similar to those of the Car-

boniferous. The earliest true reptiles appear.

2. Upper Permian. Not represented in Canada, but marine
limestones of this age occur in Kansas and westward. In
England it is represented by the important formations of the
Marl slate and Magnesian limestone ; in Germany by the copper
slate and zechstein ; and in Russia by the copper sandstones and
gypsiferous limestone.

Foesils.—Reptiles of genus Proterosaurus. Fishes of genus Palaeon-

discus. Mollusks of genera Pseudomonotis, Myalina, Productus, Fenes-
fella, &e.

“MESOZOIC PERIOD.
I. Triassic Systrem.

1. Bunter Sandstone. In Canada—Lower new red sand-
stone of the Bay of Fundy and Prince Edward Island, associated
with trappean rocks. In United States—Lower red sandstones
of Connecticut and New Jersey. In the West, red and magne-
sian limestones overlying Carboniferous of Rocky Mountains.
In Europe—Bunter sandstein of Germany, Lower Triassic red
sandstones of England.

Fossils.—Conifers and Cycads. Footprints of Dinos vurs.

2. Muschelkalk. A marine limestone found in Germany
and Eastern France, but not represented in Engiand or Kastern
America, In British Columbia and the Western United States
the Triassic sandstones and slates with voleanic rocks, and the
Monotis shales, may be partly of this age, and it may also be re-
presented in the East by part of the Triassic coal formation of
Virginia and South Carolina,

Se ee

oe eS

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Fossils (in Europe)—Encrinus moniliformis, Avicula socialis, Ceratites
nodosus, Pemphyx Sueri, &. Fishes—Hybodus, &c. Reptiles—Notho-
saurus, &.

3. Keuper Sandstone. In Canada—Upper Triassic sandstones
of Prince Edward Island and Bay of Fundy, and probably por-
tions of the Trias of British Columbia. In United States—
Upper red sandstone of North Carolina, &c. ‘T'o the Upper
Triassic are also usually referred the Mesozoic Coal beds of’ Vir-
ginia and North Carolina with their associated Sandstones and
shales. In Europe—Sualiferous series of England ; Keuper for-
mation of Germany.

Fossils.—Plants, Hquisetum, Plerophyllum, &c. Reptiles, &c., Bathyg-

nathus borealis, footprints of Dinosaurs, Labyrinthodon giganteum. The
earliest Marsupial mammals (Microlestes, Dromatherium).

Distribution of the Triassic in Canada.—This formation oc-
cupies the greater part of Prince Edward Island and the basin
of the Bay of Fundy, where its trappean beds form the ‘“ North
Mountain” of Cornwallis and Annapolis. Rocks of this age also
appear in the Rocky Mountains, in British Columbia and the
Queen Charlotte Islands; but in these Western regions their
mineral character is very different from that which they present
in the East.

II. Jurassic System.

1, Lia, Not represented in Canada, unless some of the
shales and sandstones overlying the Trias of Peace River are of
this age. Not represented in the Eastern United States, unless
some of the rocks referred to the Upper Trias are its equivalents,
In England, the gray limestones and shales of Lyme Regis, &c.
rich in Saurian remains. Similar beds with marls, &., are ex-
tensively distributed in France, Switzerland, Italy, and Suabia.

Fossils (in Kurope)—This group is rich in marine shells. Ammon-
itidae abound. Pteroceras, Paludina and other modern genera of gastro-
pods appear. Leptaena, Spirifera and other old genera of Brachiopods
become extinct. Ostrea and other recent forms of Lamellibranchs
appear. Fnaliosaurs are abundant and crocodiles of the genus Teleo-
saurus appear. Cycads and conifers are the most abundant fossil
trees,

2. Jurassic proper, or Oolitic Series. Not represented in
Canada, except perhaps by porphyrite and other voleanic rocks

in British Columbia, and shales and sandstones of Rock Island,
Peace River. Limestone and mar] of Black Hills and elsewhere
in Western United States. In Europe—Lower, Middle and
Upper Oolite of England, with the intervening Oxford and Kim-
meridge clays. Also very largely represented in France and the
Jura Mountains and elsewhere in Europe. The Lower or Bath
Oolite of England is remarkable for oolitic structure. The Stones-
field slate, a flagzy series connected with the Lower Oolite, is noted
for vegetable remains and remains of mammals and insects. The
Lithographic slate of Solenhofeu has many interesting fossils
and is of the age of the Middle Oolite. It has afforded the ear-
liest known bird, Archeopteryx macrurus. The Upper or Port-
land Oolite is overlaid by a fresh-water formation, the Purbeck,
which has afforded many mammalian remains and land plants,
and also fresh-water snails allied to Planorbis.

Fossils —Remarkably rich in Cephalopods, especially Ammonitide
and Belemnitide. Also in Reptiles, as Pterodactyls, Dinosaurs, Enalio-
saurs, Crocodileans, Turtles, &c.

III. Creracreous System.

1. Lower Cretaceous or Neocomian, In Canada—Tatlayoco
lake sandstone and conglomerate, with Aucella Piochii, and under.
lying porphyries; and perhaps the coal series of Queen Charlotte
Island and Quatseno Sound, in British Columbia; Shasta group
in California ; possibly Dakota group of Western Territories and
its extension north of the 49th parallel; Lower Cretaceous clays
of New Jersey, &c. In Kurope—Hastings sand, Weald clay, and
lower greensand of England, and their equivalents on the coutinent.

Fossils —Dinosaurian Reptiles, /gnanodon and Hylseosaurus, &c.
Appearance of Teleost fishes, and of Angiospermous Exogens of
modern types. Crioceras, Ancyloceros, and Ammonites abundant ;
Diceras.

2. Middle Cretaceous or Cenomanian. In Canada—Niobrara
limestones and clays of Western Territories and Western States
of the Union. This is an extensive marine formation, rich in
Foraminifera with Ostrea congesta and species of Inoceramus
and Baculites. In Europe—the Gault clay, Upper Greensand
and Chalk marl of England and the continent of Europe.

Fossils.—Species of Hamites, Scaphites, Turrilites, Lima, Ostrea, &c.,
are characteristic in Europe.

3. Upper Cretaceous or Senonian. In Canada—Ft. Pierre
and Fox Hill clays and sandstones of the Western Territories,
and continuation to the South. Greensand of New Jersey with
associated clay and limestone. White or Upper chalk of Eng-
land and other parts of Europe, and white limestones of North
Africa and Western Asia, Mestricht limestone of Denmark.

Fossils.—Vast numbers of Oceanic Foraminifera, especially Globi-
gerina; Coccoliths ; Sponges of genus Ventriculites, &c.; Echinoderms of
genera Ananchites, Galerites, Marsupites, Cidaris, &c.; Lamellibranchs of
genera Jnoceramus, Spondylus, Ostrea, &c., Cephalopods of genera Belem-
nitella, Baculites, Nautilus, &c., Reptiles of genera Mosasaurus, Clidastes,
Hadrosaurus ; toothed birds of genus Icthyornis, Hesperornis, &c. The
flora of this period contains a large preponderance of modern types.

Distribution.—The Cretaceous rocks occupy a broad belt ex-
tending on the 49th parallel from near the Red River to the
Souris River and thence to the north-west. They also occur on
the Saskatchewan and head waters of the Missouri farther to
.the west. Considerable areas occur in British Columbia, the
most important being that which includes the Nanaimo and
Comox coal-field on Vancouver Island.

The Cretaceous Period is remarkable, in both the eastern
and western continents, for a prevalence of estuarine and fresh-
water conditions in its earlier portion, and for a great subsidence,
~ producing oceanic conditions over wide areas now land, in its
middle and later portion. It is also marked by the decadence
of the reign of reptiles, and by the introduction of the modern
flora in the continents of the Northern Hemisphere.

KAINOZOIC PERIOD.
I. Kocenre AGE.

1, Lower Eocene (Orthrocene). In Canada this formation is
probably represented by the Lignite Tertiary formation of the
Western Territories, the Lignitic or Laramie group of the Ameri-
- can geologists, whic. “\ts of estuarine and fresh-water sand-
stones and shales, . (!: reptilian remains, lignite and fossil
plants of modern types. It is however regarded by many geolo-
gists as more nearly related to the Upper Cretaceous than
to the Eocene proper. Fig. 28, and the section on p. 33, repre-

sents parts of this group, which is very extensively distributed
in the region between the Red River and the Rocky Mountains
and thence southward. In England the typical formations are
the London clay, plastic clay and Thanet sands, holding marine
and estuarine shells and fossil fruits and wood. The Argile
Plastique and Sable Bracheux represent it in the Paris basin.
In these beds, in Europe, the oldest known placental mammals
occur, Hyracotherium, Lophiodon, Coryphodon. Marine inver-
tebrates of living species also appear, though as yet in small
numbers, about three per cent. of the whole.

Fig. 28.—Lignite Bed. Porcupine Creek, N. W.'T.—(G. M. Dawson.)

2. Middle Eocene, or Eocene proper (Nummulitic). Not
as yet recognized in Canada. In the United States this series
is represented by the clays, marls, sands and coarse limestones of
the Claiborne series of Alabama, holding marine shells and
bones of Zeuglodon. In the west the great lake basins of the
Wahstach have afforded remains of many land animals (Cory-
phodon, Tillodontia, Eohippus, &e.) In Kurope the most
characteristic and wide-spread formations are the Calcaire Gros-
sier of the Paris Basin and its associated marine sands, and the
Nummulitic limestones extending from Western Europe to
India, and marking a great subsidence. In England the Brack-
lesham and Alum Bay series are of this age.

3. Upper Eocene (Proicene.) Not recognized in Canada, Io
the United States represented by the marine clays and Orbi-
toidal limestone of Alabama, Mississippi, &c. (Vicksburg group),

to nt ah a Sa he EON BP AM PDE MS ITZ

osars Aibinaptahagh ab int «Lenina hae?

Sai tepectipirenerene rts meaniee Servcarmpige- aon

and in the West by fresh-water clays and sands (Bridger group,
&c.), containing Dinoceras, Unitatherium, Orohippus, &c. In
Europe the best known representative is the Gypseous series and
Silicious Limestone of the Paris Basin, and the upper beds of
the Isle of Wight series in England. These formations abound
in mammalian remains (Anchitherium, Palewotherium, Anoplo-
therium, Xyphodon, earliest Lemuride).

II. Miocene AGE.

1. Lower Miocene. Not recognized in Canada, unless repre-
sented by the volcanic rocks, sandstones and shales with lignite
and fossil plants of Nicola, Similkameen, &c., in the interior
of British Columbia. In America the subdivisions of the
Miocene have mot been distinctly separated, but the age is repre-
sented by the New Jersey, Virginia, &c. middle Tertiary sands,
clays, marls and infusorial deposits; and in the West by the
Middle Tertiary lake basins of White River, &c., east of the
Rocky Mountains. In the latter, three subdivisions are charac-
terized by Marsh as respectively those of the Brontotherium,
Oreodon and Miohippus. The Miocene beds hold a larger per-
centage of recent shells than the Eocene (17 tu 30 per cent.),
and abound in mammalian remains (Brontotherium, Titanothe-
rium, Oreodon, Machairodus, &c.) In Englaud—Hempstead beds
of Isle of Wight and lignites of Bovey Tracey, In France—
Calcaire de Beauce and Sables de Fontaincbleau, with equivalent
deposits in Germany, Italy, &c. The basalts of Antrim and the
Hebrides are of this age. Living genera of mammals, as Rhino-
ceros, Tapirus, Mustela, Sciurus, &¢., appear in the Lower
Miocene.

2. Middle Miocene. Falunien of France, Middle or marine
Molasse sandstone of Switzerland. Genera Mastodon, Dino-
therium, Sus, Antilope, Cervus, Felis, Dryopithecus, cc.

3. Upper Miocene. In Europe, Molasseof Veningen in Swit-
zerland, Léberon and Epplesheim beds of France, Pikermi for-
mation in Greece. Additional modern genera of mammals, as
Camelopardalis, Gazella, Hyena and Hystrix appear.

A very equable and warm climate seems to have prevailed in
the Eocene and Miocene, so that plants of genera now living in
temperate climates were abundant in Greenland and Spitsbergen.

III. Puitocene AGE.

1. Older Pliocene. Not recognized in Canada. In United
States, Sumter clays and sands of North and South Carolina.
In the West, Loup River group of Niobrara, containing remains
of Camel, Rhinoceros, Horse, &. In England, Coralline Crag
and Red Crag.

2. Newer Pliocene. Not recognized in Canada, nor distin-
guished in the United States from the older Pliocene. In Eng-
land, Norwich Crag and Chillesford Clay.

In the Pliocene, the percentage of recent shells rises to 50 or
more. Mammalia of modern genera are abundant, and a few
modern species appear. In the later Pliocene the land both of
Europe and America seems to have been more elevated and
extensive than at present (First Continental period of Lyell).
The climate of the Northern Hemisphere was cooler than in the
Miocene.

IV. PLEISTOCENE AGE,

This was characterized throughout the Northern Hemisphere
by a great refrigeration of climate, followed or accompanied by
a submergence of the land to a depth exceeding in some places
5000 feet. The formations of the period are well represented in
Canada, and may be taken as types, more especially as from
their great extent and uniformity they are free from some of the
complications which have caused controversy elsewhere.

1. Boulder Clay. At the beginning of the Pleistocene the
land was higher than at present. At this time the mountain
tops were extensively occupied with glaciers, which have left
their traces in all the elevated ground. Very deep valleys and
ravines were also excavated by the rivers. Beds of peat wore
accumulated, and gravels and sands in low grounds, in lake
basins and on coasts. Gradual subsidence then set in, under
which the valleys were invaded by cold Arctic currents laden with
field ice and bergs, while the high levels still sent down glaciers,
Under these circumstances moraines were formed on the land,
and sheets of stony clay with boulders in the sea, forming what
has been termed the boulder clay or “ Till,’ and extensively
polishing and striating the surfaces of rocks.

In the deposits of this period Arctic shells are found, though
‘not abundantly, and also trunks of boreal coniferous trees. At

an Ba

Pn SS ORS te ches fy al ie tke earache 3S

peso aba ae

Fig. 29.—Boulder (11 feet long) on glaciated surface. Lake of the
Woods.

the beginning cf the age, however, there were in Europe and
America forests of temperate and boreal type, and a great
number of mammals, some extinct, some still surviving, and pre-
senting a remarkable mixture of boreal and temperate forms.
Remains of these occur in peaty beds under the boulder clay.
By the progress of the glacial cold and subsidence, these animals
were destroyed or compelled to migrate to the southward.

2. Leda Clay, Erie Clay. This marks the greatest subsid-
ence and the gradual emergence of the land. It is a fine stratified
clay, sometimes however with large boulders, and thus passing
into boulder clay. It has on the Atlantic slopes of America and
Europe numerous marine fossils, especially in its upper part ;
and these are mostly of species still inhabiting the North Atlantic
and North Pacific. Farther inland it contains some remains of
plants and land animals. The Leda clay is equivalent to the
Clyde beds and Uddevalla beds of Europe. There is reason to
believe that the great snbsidence which closed in this period
reached to 2300 feet in the mountains of Wales, and to 4000
feet in those of North America. It was probably greatest to-
ward the north. At the beginning of the deposit of Leda clay,
the shells indicate cold water covered with floating ice. Toward
its close (Upper Leda clay or Uddevalla beds) the marine climate
must have been little different from that now occurring in the
same latitudes on the western side of the Atlantic.

3. Saxicava Sand and Second Boulder Drift. This marks
the re-elevation which ended in a second continental period,
raising the continents to a greater elevation than at present.

The climate was still somewhat cold, and large boulders carried
by floating ice abound in the Saxicava sand, but are most abun-
dant at its base.

The Pleistocene deposits are sometimes called Quaternary ;
but there is no good ground for separating them from the Kaino-
zoic or Tertiary. The term “ Champlain ’’ deposits has been ap-
plied to them in the United States; but the Lake Champlain
beds are those of a limited valley among mountains and are not
typical or characteristic.

Some writers include in the Pleistocene the next or post-glacial
age; but it is more nearly connected in its physical conditions
and its animal life with the modern period.

Dawkins catalogues, for this period in Britain, 1 mammal sur-
viving from the Pliocene and still living, 7 surviving from Plio-
cene and extinct, 67 new species, of which 14, including elephants
and other large and important species, are now extinct.

V. MopgERN AGE.

This extends from the close of the glacial or Pleistocene age
to the present time, and is divisible into two well-marked periods.

1. The Post-Glacial. (Second Continental Period of Lyell.)
In this the land of the Northern Hemisphere was more extensive
than at present. The climate was temperate but somewhat ex-
treme. All the modern mammals, including man, seem to have
been in existence, but several others now extinct, as the Mam-
moth, the Tichorhine Rhinoceros and the Cave Bear, lived in
the Northern Hemisphere, and many still extant differed very
remarkably in their geographical distribution from that of the
present time. To this period belong the human remains of the
early cave deposits and river gravels of Europe, or of the
‘““Mammoth age” (Palawocosmic or Paleolithic age). This
period was terminated by a submergence or series of submer-
gences which with their accompanying physical changes proved
fatal to many species of animals and to the oldest races of men,
and left the continents at a lower level than at present, from
which they have risen in the recent period. In Britain Dawkins
catalogues 22 living and 6 extinct species survivors of the Pleis-
tocene in this period, and 18 new forms still living. The 6
extinct species include 2 species of elephant, 2 of rhinoceros, the

a a Pm ie Nn. es

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cave bear, and the great Irish elk. It is evident therefore that
man comes in with a fauna in the main modern, but including a
few large and important species which have perished since his
advent, and many others which have much changed their range.

2. The Recent or Historic Period. This dates from the
settlement of our continents at the present levels after the Post-
glacial subsidence. It is the period of Neocosmic or Neolithic
men of races still extant. I have called this the Historic Period,
because in some regions history and tradition extend back to its
beginning. The historical deluge is in all likelihood identical
with the movements of the land above referred to, by which this
age was inaugurated ; though in certain localities, as in America,
the beginning of the historic period is very recent. In this age
man coexists wholly with existing species of mammals, and the
races of men are the same which still survive. The whole
forms geologically one period, and the distinctions made by
antiquarians between stone, bronze and iron ages, and under the
former between paleolithic and neolithic, are merely of local
significance, and connected with no physical or vital changes of
geological importance.

" OSSIL.

ENTIAN I

Laur

Nature-pzinted,

imen.

spec

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20
im
5
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Bozoon Canadense.

LAURENTIAN Fossi.s.

Eoxoon Canadense. (1) Small specimen disengaged by weathering.
(2) Acervuline cells of upper part—magnified. (3) Tuberculated
surface of lamina—mag. (4) Laminw of Serpentine in section, re-
presenting casts of the sarcode—mag. (5) Section magnified showing
canal system at (4) and tubuli at (a). (6) Canals highly magnified.

nocd arc ay

Hvuronian Fossi.s.

Fig 1. Cast of worm burrows, Madoc (Hastings group)—magnified. 4
a. Containing rock. 0. Space filled with calcite. c. Sand agglutin-
ated and stained black. d. Sand uncoloured. Figs. 2,3. Another spec-
imen, nat. size, and mag. Fig.4. Eozoon Bavaricum x 25 (after Gumbel). 4
a, 0, calcite. c. tubuli. d, ¢. Casts of contorted chambers. Fig. 5. fl
Arenicolites. Fig.6. Aspidella terranovica—Billings. The two last from:
Upper Hursnian of Newfoundland.

-
TES tm apd

‘ni

Mippie CamBrian Fossi.s.

Fig. 1. Paradoxides Micmac. 2. Conocephalites (Conocoryphe) Matthews.
3. Orthis Billingsi. 5. Discina Acadica. 4. Lingulella Matthewi.—Aca-
dian group, St. John, N.B.

SSN aS i es ee eR oes 22S ee renew

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Fig. 1. Protichnites septem-notatus, Potsdam.
2. Ligulella antigua. (¢c) Short variety. (d) Long variety?

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SILURO-CAMBRIANJFossits, (Quebec Group.)

ig. 1. Phyllograptus typus. 2. Graptolithus Logan’.
i 3. Keeuliomphalus intortus. 4, Bathyurus Saffordi,

5. QDikelocephalus magnifieus,

aebanetietidicenenaaamiane = ir mnt nese
Sn ie AO OE ANTRAL AI 2 ON

porte | au Ge SEs viy:
CALAN sea MER Le, CREB Eee

fibrosa.
7. Orthis pectinella.
10. Orthis testudinaria.
13. Murchisonia gracilis.

umbilicatula. 16. Orthoceras sp.

Graptolithus bicornis.
4. Ptilodictya acuta.

SILURO-CAMBRIAN FossiLs.

2. Petraia profunda.
5. Lingula quadrata.
8. Rhynchonella increbrescena.
11. Strophomena alternata,
14. M. bicineta,
17. Calymene senaria.

i009) 9H) Fra

—_
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Discina circe.
12. Bellerophon
15. Pleurotomaria

\ Ott nt 1 st tts
——

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ing
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See

ERIAN oR DEVONIAN FoOssiLs.

1, Zaphrentis prolifica. 2. Heliophyllum Halli.

3. Sptrifer mucronatu’, 4, Pterinea flabella.

5, Platephemera antiqua. 6. Jaw of Dinichthys (reduced).
7. Cephalaspis Dawsont (reduced). (a) Sculpture.

Erian or Drvonian PLANts.

1. Archaeopteris Jacksoni, (a, 6) portions showing venation.
2. Sphenophyllum antiquum, (a) magnified, (4) natural size.
3. Asterophyllites parvula, (a) nat. size, (4, ¢) portions magnified

Ba ro SSIIVWUON BhAmwek
SSR a! Mes Mh so Aieaowin

aun

MWY

a dadanonce

TNT
LD,

Lower Carroyirerous Fossine.
2. Chetetes tumida. 3. Lithostrotion Pic-
5. Spirifer cristata. 6. Centronella anna.
8. Athyris subtilita. 9. Cardiomorpha
11. Conularia quadrisulcata.
14. Loxonema acutula.

17. Phillipsia Howi.

Fig. 1. Stenopora extlts,
4. Spirifer acuicostata.

7. Productus semireticulatus.
10. Aviculopecten simpler.

vindobonensts.
12. Naticopsis dispassa. 13. Murchisonia gypsea.
15. Nautilus avonensis. 16. Orthoceras vindobonense.

toense.

pts ‘ , i

“COAL-FORMATION FossILs.

Fig. 1. Pupa vetusta. 2. Conulus priscus. 3. Spirorbis carbonarius.
4. Entomostracans, (a) Bairdia, (b) Cytherella, (c) Cythere. 5. Millipedes,
(a) NXylobius sigullarie, (b) Archiulus Xylobioides, (c) Yylobius farctus,
6. Blattina Bretonensis. 1. Blattina Heert.

TVANMON BINWMOU OC
PRE AM cnet Peat hdare shen Hes

CARBONIFEROUS CALAMITER.

Calamites Suckovii, restored. Leaves.

Foliage. Leaf enlarged.

Ribs and Scars. } Leaves of C. nodosus.
Roots. Whorl, enlarged.
Base of stem. Structure of stem.
Calamites Cistii, restored. | Vebsels, magnified.

SSS

S
SS
Ye . 4

(vA

CARBONIFEROUS LEPIDODENDRA.

A Branch and leaves of Z. Pictoense, 3 nat. size. A® Leaf. AS Twig

and leaves, 4. A4 Portion of bark, #4. A5 Leaf-scar. A6 Bark
of old stem furrowed by growth, #. A7 Cone, 3.

. personatum, leafy branch, #. B2 Portion of bark, 3. BS Arcole
enlarged. B¢ Leaf.

|. plicatum, bark of old stem.

. rimosum, old stem with furrows, 4.

. undulatum, showing furrows and scars of cones, 3.

CARBONIFEEOUK SIGILLARLA.

A Sigillaria Brownii, restored. BS, elegans, restored. B! Leaf ot S. elegans

B2 Portion of decorticated stem, showing one of the transverse bands of
fruit-scars.

83 Portion of stem and branches, reduced—and scars, nat. size.

C Cross section of S. Brownii (2), reduced, and portion at (M), nat. size.
(a) Sternbergia pith, (47) Scalariform vessels, (62) Discigerous
cells, (c) Inner bark. (d) Outer bark.

0 E ‘Tissues, may. F Sigillaria Bretonensis, j. |

t S. striata. HOS. emrnens,
reduced. I 8. catenoides. KS. planicosta, 1. Leaf

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CARBONIFEROUS FERNS.

Odontopteris subcuneata (after Bunbury ).

Neuropteris cordata
Alethopteris lonchitica.
Dictyopteris obliqua (after Bunbury.)
Phyllopteris antiqua, mag. (E1) nat. size.
Neuropteris cyclopteroides.

do.

PLANTS OF THE PBRMO-CARBONIFEROUS.

(Prince Edward Island.)

(a) Walchia gracilis. (6) W. robusta.
(ce) Calamites gigas. (d) Pecopteris arboreacens

Edward Island.)

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2. Araucarozylon E

Jurassic Fossine.

1. Head of Megalosaurus. 2. Plerodactylus crassirostris
3. Ichthyosaurus communis. 4. Tail of Archwopteryz.
5. Ammonites Jason. 6. Belemnites (section).

x 100

Cretackous Fossins. (Western America.)

1. & 2. Scales of Teleost Fishes, N. W. Territory.

3. Trigonia Americana. 4. Inoceramus Vancouverensis.
5. Baculites ovatus. 6. Foraminifera, Boyne R., Manitoba,
)) Textularia globulosa, (b) 1. pygmaea, (c) Pla orbulina ariminensis.

Katnozoic MAMMALS.

1. Coryphodon hamatus (Eocene).

2. Leuglndon cetioides—tooth (Eocene).

3. Dinoceras mirabilis (Eocene).

4. Oreodon major (Miocene). (All reduced.)

PLEISTOCENE Fossis.

. Rhynchonella psittacea. 6. Tellina (Macoma) calcarea.

. Mytilus edulis. 7. Mya truncata.

. Sazicava rugosa. 8. Astarte (Nicania) Laurentiana.

. Leda (Portlandia) arctica. 9. Natica clausa.

- Tellina (Macoma) Grenlandica. 10. Fusus tornatus (Neptunen despecta)
11. Scalaria Grenlandica.

‘(UISPOUL PUB 3U9904SIA[q) sNUDI IWF UOpozsD A

Fig. 1. Shrinkage cracks Carboniferous (reduced).
2. Rain-marks, (a) modern, (dc) Carboniferous.
3. Rill-marks, Carboniferous (reduced).

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